-J 1 p 



P4 



ARE SOILS MAPPED UNDER A GIVEN TYPE 

NAME BY THE BUREAU OF SOILS 

METHOD CLOSELY SIMILAR 

TO ONE ANOTHER? 



A THESIS SUBMITTED IN PARTIAL SATISFACTION OF 

THE REQUIREMENTS FOR THE DEGREE OP 

DOCTOR OF PHILOSOPHY 

AT THE UNIVERSITY OP CALIFORNIA 



ROBERT LARIMORE PENDLETON 



O \ '-^1 



^ 



UNIVERSITY OF CALIFORNIA PUBLICATIONS 

IN 

AGRICULTURAL SCIENCE 

Vol.3,No. 12, pp. 369-498, plates 43-74, 33 text figures June 30, 1919 



ARE SOILS MAPPED UNDER A GIVEN TYPE 

NAME BY THE BUREAU OF SOILS METHOD 

CLOSELY SIMILAR TO ONE ANOTHER? 



ROBERT LARIMORE PENDLETON 



UNIVERSITY OF CALIFORNIA PRESS 
BERKELEY 



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Gift 



A UNIVERSITY OF CALIFORNIA PUBLICATIONS 

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S^\D AGRICULTURAL SCIENCE 

•" Vol. 3, No. 12, pp. 369-498, 33 text-figs., pis. 43-74 June 30, 1919 



ARE SOILS MAPPED UNDER A GIVEN TYPE 

NAME BY THE BUREAU OF SOILS METHOD 

CLOSELY SIMILAR TO ONE ANOTHER? 

BY 

EGBERT LAEIMOEE PENDLETON 



CONTENTS 

PAGE 

Foreword 369 

Introduction 370 

Need of a classification of soils 371 

Historical development of the classification of soils 371 

Plan of the present study 376 

Discussion of results 377 

Mechanical analysis 380 

Chemical data 395 

Bacteriological data 414 

Greenhouse data 432 

General discussion 467 

Summary 481 

Appendices 48.H 

A. Methods and technique 483 

B. Soil sample locations 490 

FOREWORD 

It is due the author, as well a.s to the undersigned, that a few 
words be said by way of preparing the reader for what follows in this 
paper. It will be observed, first, that the manuscript was, for an 
unusually long time, in the printer '.s hands. Those who appreciate, 
as few do today, the great rapidity with which the theories and the 
methods in soil and plant study change, will readily catch the signifi- 
cance of the foregoing sentence. INfuch of the work done by Jlr. 
Pendleton and some of the methods used may now properly be con- 
sidered obsolete, or, conservatively speaking, at least obsolescent. 
Nevertheless, I deem it of some importance to give the results obtained 
in more or less detail, because of their historical value, and because Mr. 



370 University of CaHfornia Publications in Agricultural Sciences [Vol. 3 

Pendleton's residence in India since the paper was written by him 
has rendered satisfactory changes and deletions practically impossible. 
Under these cirenm.stances, with the burden of preparing the paper 
for the press and the reading of the proof falling to me. the author 
cannot well be held responsible for the inaccuracies and the infelicities 
of expression which have been carried over from the original manu- 
script without change. iMoreover, the investigation was carried out 
under my direction, and the plan of attack on the problem, together 
with the methods employed, were suggested by me. ]VIucli that, in the 
light of present knowledge, is superfluous or patently inexact or 
erroneous in the paper is due to points of view held by me in 1915, 
but now happily discarded. For all these, I as.sume the entire 
responsibility, and absolve I\Ir. Pendleton in that regard. 

On the other hand, the work having been carried out at my .sugges- 
tion and under my direction, I feel constrained, in justice to myself, 
to say that the views expressed in this paper, and the conclusions 
drawn are wholly Mr. Pendleton's and are not in agreement with those 
held by me. I fail to see the cogency of the arguments set forth for 
soil elassifieation and mapping at this juncture in soil studies, and 
cannot admit the pertinence of the analogy between classification of 
other objects and of soils which the author of this paper employs. 
My own general conclusion from the results obtained by Mr. Pendle- 
ton is that they cast grave doubt on the validity of the Bureau of Soils 
method of soil ela.ssification and mapping, and, incidentally on all 
methods devised for that purpose to date. I cannot see how such 
methods can serve us in scientific work at all, and, from the practical 
standpoint, it would surely seem that guides for the purchaser of land 
could be arranged more cheaply and less elaborately than by the soil 
mapping methods extant. This statement has particular reference to 
the subdivision of types very minutely, such as, for example, .sandy 
silty clay, clay loam adobe, etc. Such minute classification and sub- 
division in view of the present state of our knowledge of soils, is 
analogous, in my opinion, to carrying figures out to four decimal 
places when it is known that the accuracy of the method makes it 
impossible for them to be correct beyond the first decimal place. In 
support of this seemingly radical conclusion, the reader will find much 
of interest in the recent studies of this laboratory on variability in 
soils, which have already appeared in this same series. 

Chas. B. Lipman. 



INTRODUCTION 

For several years the University of California has been cooperating 
with the United States Bureau of Soils in the mapping of the soils of 
the agricultural portions of the State of California. The system of 
mapping used is that developed by the Bureau of Soils. During the 
year 1914—1915 the writer, representing the University of California, 
was engaged in some of this soil survey work. In that year, in the 
field, many questions arose regarding the criteria used, the methods. 



1919] Pendleton: A Study of Soil Types 371 

and the results of the scheme of mapping. It was thought that pos- 
sibly some of the many questions could be answered through a labora- 
tory study of some typical soils. This paper is a description of cer- 
tain parts of the work done in this connection. 



THE NEED OF A CLASSIFICATION OF SOILS 

Since soils consist of a number of more or less distinct groups thej' 
are fitting subjects for classification. In fact, it is my belief that it 
is as necessary to have a classification for soils as for any other group 
of natural objects in order that "the various and complex relations 
may be shown as far as practicable,"' and that there be a definite 
basis for sj'stematic and thorough investigations.- The advantages of 
a classification of soils are apparent. But because soils grade gradu- 
ally into one another, rather than exist as discrete individuals which 
can be more easily considered and treated from a sj'stematic stand- 
point, the problem of evolving a satisfactory classification has been 
particularly difficult. The many and diverse classifications proposed, 
and the difficulty of applying manj^ of these classifications under con- 
ditions otlier than those for which they were evolved, testify to the 
difficulty of the task in question. 

The mapping of soils without a classification is impossible, and 
so a brief summary of the development of soil mapping will bear a 
close relation to the development of soil classification. 



HISTORICAL DEVELOPMENT OF THE CLASSIFICATION 
OF SOILS 

The early historj- of the making of soil maps is that of geologic 
maps as well, when soils, from the agricultural standpoint, and the 
less distinct geological formations as such, were not sharply distin- 
guished. Blanck^ has an excellent treatment of the development of 
soil mapping and of the modern continental European conceptions of 
the nature and significance of soil maps. According to Blanck the 
earliest record of a proposal to make a map to show something of the 
nature of the actual material composing the surface of the earth is 
that of Lister's proposal, in 1683, to the Royal Society of London. 



1 Coffey, G. N., Proc. Amer. Soc. Agron., vol. 1 (1909), p. 17.5. 

2 Cameron, F. K., Eighth Internat. Cong. Chem., vol. 26 (1912), sees, via-xib; 
app. pp. 699-706. 

sFuhling, Landw. Ztg., vol. 60 (1911), pp. 121-45. 



372 University of California Publications in Agricultural Sciences [Vol. 3 

But it was not until 1743 that Paeke executed a map of Kent, showing 
the occurrence of minerals by symbols. Apparently the next advance 
was by the Germans, when Piichsel, 1773, and Gloser, 1775, first used 
colors to show granite, limestone, etc. This work constituted the first 
real geologic map in the modern sense. There was not much activity 
in this line of geologic work until 1870 or later. Such activity as there 
was showed a lack of emphasis on soils in the agricultural sense of 
the term. 

The work on the geologic drifts of northern Europe, and .studies of 
the more recent lowland formations and soils of Germany led to soil 
mapping. The first real soil map, according to Blanek, was prepared 
by Benningsten-Porder of Halle, in 1864-67 ; while Garnot* states 
that in 1863 M. Scipion Gras used superposable maps of the Depart- 
ment of Isere, showing (1) geology, (2) . agricultural soils, (3) alti- 
tudes of agricultural regions, and (4) culture. The first true geologic- 
agronomic map published by the Preussischegeologische Landesan- 
stalt appeared in 1878. 

The school of soil classification and mapping just mentioned, using 
the geologic maps and methods as a point of departure have evolved 
numerous though similar systems of recording the agrogeologic data 
on the map. The geologic formation is shown by the color, and the 
soil textures by symbols, while one or more of the following groups 
of data appear and may be shown : topography by contours, subter- 
ranean water by blue figures, location of borings in red with figui'es 
referring to tables, amount of plant food elements or substances by 
figures or hatchings, varying directions, color, or nature of lines, etc. 
The nature and amount of the data shown and the manner of repre- 
senting them vary a great deal. Some soilists, to use a term proposed 
b}' Coffey,'' advocate and use superposable maps to show one or more 
groups of data, thus avoiding unnecessary confusion on the main map. 

Hazard" proposed a scheme of classification which is quite as 
directly connected with the economic factors controlling the crops 
grown, and with the assessable valuation of the land, as with the 
actual or potential fertility of the soil itself. There are several classi- 
fications of this t}-pe, involving the assessable values of the land. 



* Eapport sur Ics cartes agronomiques. Bull. Min. Agr. France, 1893, no. 8, 
pp. 956-73. 

5 Jour. Amer. Soc. Agron., vol. 8 (1910), p. 239. 

eLandw. Jahrb., vol. 29 (1900), pp. 805-911. 

Gregoire, A., and Halet, F., Bull. Inst. Chem. et Bact. Gembloux, 1906, no. 75, 
pp. 1-43. 



191!)] Fendleton: A Study of Soil Types 373 

This development of tlie mapping of soils as an outgrowth of areal 
geology in France and Germany may be contrasted with the develop- 
ment of soil classification from other viewpoints, such as tliat of the 
Russian school. In Russia there is not the predominance of residual 
and shallow soils which characterize much of western Europe and 
which in France especially have led to the adoption of the geologic 
basis of classification. Dokoutchayev and Sibirtzev have been the 
chief proponents of a classification of soils based upon the ' ' conception 
of a soil as a natural body having a definite genesis and a distinct 
nature of its own."'" 

The genetic conditions of the formation of natural soils include 
the following variable factors which cause variation : 

(1) The petrographic type of the parent rock; (2) the nature and intensity of 
the processes of disintegration, in connection with the local climatic and topo- 
graphic conditions; (3) the quantity and quality of that complexity of organisms 
which participate in the formation of the soil and incorporate their remains in it ; 
(4) the nature of the changes to which these remains are subjected in the soil, 
under the local climatic conditions and physico-chemical properties of the soil 
medium; (5) the mechanical displacement of the particles of the soil, provided 
this displacement does not destroy the fundamental properties of the soil, its geo- 
biological character, and does not remove the soil from the parent rock; and (6) 
the duration of the processes of soil formation. 

Upon this genetic basis there has been developed a series of soil zones, 
ranging from the laterite soils in the tropics to the tundras in the 
Arctic regions. The outstanding and controlling factor in the scheme 
proposed is the relation of these zones to climate. For this reason the 
statement usually seen is that climate is the basis of the classification.^ 
There are nearly as many groups of intra-zonal and azonal soils as 
of those belonging to the zones proper. The former include alkali, 
marshy, alluvial, and other soils. 

Hilgard, while actively interested in the genetic viewpoint of soil 
classification, was the foremost proponent of a classification upon 
the basis of the natural vegetation growing upon the soil." This 
criterion is not al'^pays available, though some groups of plants, as the 
alkali tolerant ones, are almost invariably present where the condi- 



7 Exp. Sta. Eecord, vol. 12 (1900), p. 704. 

See also Sibirtzev, Cong. Geol. Intern., 1897, pp. 73-125; abstract in Exp. Sta. 
Rec, vol. 12 (1900-01), pp. 704-12, 807-18. 

Tulaikoflf, N., The Genetic Classification of Soils, Jour. Agr. Sci., vol. 3 (1908), 
pp. 80-8.5. 

8 Coffey, U. S. Bur. Soils, Bull. 85 (1912), p. 32; Jour. Amer. Soc. Agron., 
vol. 8 (1916), p. 241. 

9 Hilgard, E. W., Soils (New York, Macmillan, 1906), pp. 487-549. 



374 University of California Fuhlications in Agricultural Sciences [Vol. 3 

tions are unfavorable for the less resistant plants. Later Hilgard 
and Loughridge'" claimed that it is impracticable to attempt "a sat- 
isfactorj' tabular classification in which each soil shall at once find its 
pigeonhole prepared for it . . . because the subject matter is as yet 
so imperfectly known." However, this does not dispute the justifica- 
tion for making classifications for specific purposes or of specific 
regions. With respect to this point there seems to be confusion. The 
question is not whether soils can be classified at all or not, for every 
observant farmer classifies the soil with which he is familiar, but 
whether a satisfactory classification is possible over a large territory, 
where soils are subject to the varj-ing action of the important soil 
forming agencies. 

Still another type of soil mapping is that of Hall and Russell, 
which is given in their admirable Report on the Agriculture and Soils 
of Kent, Surrey, and Sussex."'^ In this district the soils are largely 
residual, and form quite distinct groups, depending upon the parent 
geologic formation. These groups of soils, such as the Clay-with- 
flints and the Thanet beds, have very definite agricultural properties ; 
hence the treatment of all phases of agricultiire upon each separate 
group of soils. Hall and RusselP^ present an excellent discussion of 
the methods of soil classification and the interpretation of the soil 
analyses used in their study. Ru.sselP^ gives a very similar though 
briefer treatment. 

There are other more or less specialized classifications that have 
been applied to local conditions and problems. As an example may 
be cited Dicentj^'s work on grape soils.'^ 

Various modifications of the above schemes of classifying and map- 
ping soils are found in general texts on soils.^^ Nowacki^" proposes a 
curious system. Genera et Species Terrarum. It is in Latin terminology. 
The genera are based on the quality of the soil, whether stony, sandy, 
clayey, peaty, etc., and the species are dependent upon the quantities 
of organic matter and clay. 



i" The Classification of Soils, Second Intern. Agrogeol. Conf., Stockholm, 1910, 
p. 231. 

11 London, Bd. Agr. and Fish., 1911. 

12 Jour. Agr. Science, vol. 4 (1911), pp. 182-223. 

13 Soil Conditions and Plant Growth (London, Longmans, 1913), pp. 132-48. 
1* Die ampelogeologische Kartierung. First Intern. Agrogeol. Cong., Budapest, 

1909, pp. 257-71. 

15 Ramann, E., Bodenkunde, Berlin, Springer, 1911. 
Mitscherlich, E. A., Bodenkunde, Berlin, Parez, 1905. 
lePraktisehe Bodenkunde (Berlin, 1892), pp. 130-80. 



1919] Pendleton: A Study of Soil Types 375 

Soil Surveying in the United States. — In a brief way, it has been 
shown how there arose the different systems of soil classification. 
Only a few typical systems of classifications, and something of the 
reasons for the divergences, have been mentioned.^' Probably the one 
agency that has carried on the most extensive soil classification and 
mapping is the Bureau of Soils of the United States Department of 
Agriculture. It is now proposed to discuss and in a measure criticize 
the work of the Bureau of Soils, the one organization that has, more 
than any other, succeeded in applying a detailed system of soil classi- 
fication over extensive areas. 

The problems that the Bureau had to face during its early exist- 
ence were special studies of the soils of certain crops, especially of the 
tobacco districts.^* Later the soil utilization work of the Bureau of 
Soils was transferred to other branches of the Department of Agri- 
culture, leaving as the main task for the Bureau the systematic classi- 
fication and mapping of the soils of tlie United States. 

Coffe.y'^ has so well discussed the present day conceptions of the 
bases for the classification of soils, that it does not seem necessary to 
repeat any portion of that excellent statement here. He showed that 
the Bureau of Soils, in its method of classifying soils, uses a combina- 
tion of a number of systems. This matter is dealt with more in detail 
in an article by Coffey,-" and the Report of the Committee on Soil 
Classification of the American Society of Agronomy.^^ The question 
often arises as to the validity of making the close distinctions regard- 
ing color, texture, geologic origin, etc., and is one which should be 
dealt with in order to render less empirical the nature of most of the 
criteria which are used at pre.sent. See the Report of the Committee 
on Soil Classification and Mapping.-- 

Because of different views regarding soils and soil fertility from 
those held by the Bureau of Soils, the Illinois Agricultural Experi- 
ment Station has undertaken a soil survey and classification, under the 
direction of Dr. C. G. Hopkins, which is independent of the Bureau 



17 See Coffey's excellent treatment of the soil survey work in this country. 
The Development of Soil Survey Work in the United States with a Brief Reference 
to Foreign Countries, Proc. Amer. Soc. Agron., vol. 3 (1911), pp. 115-29. 

18 Whitney, Extension and Practical Application of Soil Surveys, Off. Exp. 
Sta., Bull. 142 (1903), pp. 111-12; The Purpose of a Soil Survey, U. S. Dept. 
Agr., Yearbook, 1901, pp. 117-32. 

laA Study of the Soils of the United States, U. S. Bur. Soils, Bull. 85 (1912), 
pp. 24-38. 

20 Jour. Amer. Soc. Agron., vol. 8 (1916), pp. 239-43. 
21 /bid., vol. 6 (1914), pp. 284-88. 
2ilbid., vol. 8 (1916), pp. 387-90. 



376 University of California Publications in Agricultural Sciences [Vol.3 

of Soils, and differs from its methods in a number of ways. Since the 
soils of Illinois are of a much narrower range of variation than are 
those of the whole of the United States, the system of classification 
for the state need not be so elaborate. The soils are divided accord- 
ingly as they have been glaciated or not, and if glaciated, in what glaei- 
ation period. They are further divided according to color, topogra- 
phy, and texture of soil and subsoil.-^ Correlatioji of the types of 
soil mapped in the various areas, one of the greatest sources of criti- 
cism of the Bureau of Soils survey methods, is more easilj' handled 
in the Illinois work, since it is possible for the one in charge of the 
work to pass personally, while in the field, upon all correlation and 
the establishment of all new types. " It is insisted that the field men 
map accurately and in sufficient detail. This insures the accuracy of 
the maps as regards the standards adopted, the infonnation is specific, 
and the local users of the maps are not misled.^* In connection with 
the field classification and mapping, pot and plot cultures are carried 
on, not so much to test the relative fertility of the untreated soils, but 
to determine the effects of the application of various sorts and quanti- 
ties of fertilizers. Hopkins,-'^ to show the differences in detail between 
the U. S. Bureau of Soils mapping and that of the Illinois Experi- 
ment Station, compares a U. S. Bureau survey of 1902 with a state 
survey publislied in 1911. This is not entirely fair, because with the 
increase of field knowledge of soils gained b.y them and the realiza- 
tion of the need of representing the soils in more detail, a survey 
made by the Bureau in 1911 would almost certainly show much more 
detail and show it with greater accuracy than the maps made in the 
early period of the work. This point may be strengthened by the 
notes given below on the comparison of a portion of an early survey 
made in southern California by the Bureau of Soils with a recent 
survey of the same soils made by the Bureau and the University of 
California working in cooperation. 

PLAN OF THE PRESENT STUDY 

The present study is an attempt to see if certain soil types mapped 
as the same from different areas in the state of California, and judged 
to be the same by the criteria ixsed by the Bureau of Soils, are the 



23 Hopkins, Soil Fertility and Permanent Agriculture (Boston, Ginn, 1910), 
pp. 54-57. 

24 Ibid., p. 115. 

25 Ibid., pp. 114-15. 



1919] Pendleton: A Study of Soil Types 377 

same or similar when examined from the laboratory stauclpoiut. For 
examjjle, we may take the Hanford fine sandy loam, which is one of 
the types that has been used in the present study. According to the 
criteria of color, mode of formation, origin (as judged by the presence 
of mica), nature of subsoil, texture, etc., this soil has been found and 
mapped in a number of areas that have been mapped in this state. 
But will these various bodies of soil, from widely separated portions 
of the state, when judged by laboratory and greenhouse studies on 
samples as uearl}' representative as possible, appear to be the same or 
similar ? 

The types selected for such a study as this should fulfil the follow- 
ing conditions: first, they should have at least a reasonably wide dis- 
tribution in the state so as to have been mapped in a number of differ- 
ent soil survey areas; and second, the several types should be repre- 
sentative of different classes of soils (clays, loams, sandy loams, etc.), 
so that contrasts could be obtained between the types. 

In the collection of samples it was aimed to obtain representative 
samples from each of a number of bodies of soil of the types selected ; 
not to obtain possible variations from the ideal in any one body. In 
the laboratory the soils were compared with regard to their physical 
composition in the surface horizon, to their chemical composition in 
three horizons, and to their relative bacteriological activities. In the 
greenhouse the soils (surface horizon only) were placed in large pots 
and their comparative ability to produce various crops was studied. 

No claim is made that these criteria should be the ones used in 
determining the systematic classification of soils or in determining 
the relative fertility of the soils. They were merely used to determine 
how nearly the soils classed under a given type name agree from the 
standpoints named. 

DISCUSSION OF RESULTS 

The bacteriological and chemical determinations were I'un in dupli- 
cate so that the figures presented are averages. It is considered that 
this gives fairer figures for comparison, especially since the determina- 
tions were run on separate samples, and not on aliquots of a single 
solution from a single sample. 

There is a very important factor which should always be kept in 
mind especially when considering the bacteriological and greenhouse 
comparisons. This is the factor of the probable error. Though the 



378 University of California Publications in Agricultural Sciences [Vol.3 

advisability of judging all results in the light of the probable error 
is admitted, no attempt has been made to apply this factor to the 
results reported in this paper. As the result of the effect which such 
a factor might have upon the results of bacteriological determina- 
tions carried on only in duplicate, or upon the results of greenhouse 
work done in triplicate, one hesitates to draw conclusions, especially 
those based upon minor variations. Hence in this work only the more 
marked results will be considered of significance. 

When planning the work it was thought that three or four samples 
of a type would be enough to show whether or not a given type was 
approximately uniform, or widely variable, and as to whether the 
types were similar to one another, or quite dissimilar. But it now 
seems, after comparing the determinations run on the larger number 
of samples of the Hanford and San Joaquin types, 9 and 8 respec- 
tively, with the determinations run on the Altamont and Diablo types, 
of which there were a much smaller number of samples, 3 and 4 
respectively, that the larger series gives a much better insight into the 
variations of a given type and affords a much better basis for con- 
clusions. 

Hence, as regards the laboratory work thus far carried out, the 
emphasis has been placed upon the Hanford fine sandy loam and the 
San Joaquin sandy loam. Determinations have not been completed 
on the Altamont and Diablo series to the extent that they have on the 
former two. 

It is of no little significance that the Hanford fine sandy loam and 
the San Joaquin sandy loam are very widely contrasted soils agricul- 
turally. The Hanford is typical of good recent alluvial soil in this 
state ; while the San Joaquin is typical of wide expanses of ' ' old valley 
filling" soils that are considered poor as regards crop producing 
power and are underlain by compact iron-cemented hardpan. Conse- 
quently, the results of comparing soils so different from an agricul- 
tural point of view, and so radically different as regards soil survey 
criteria (though the textures are quite similar) will be of considerable 
interest. They are of greater interest than the comparisons between 
the Diablo and Altamont soils, as the latter are quite similar in agri- 
cultural value and use, as well as in field appearances. Between the 
Diablo or Altamont and the Hanford or San Joaquin one cannot 
judge as closely regarding variations, for the soils are so radically 
different. On the other hand, one can compare the soils of the heavy 
and light types to see to' what extent the chemical and bacteriological 
results differ as compared with the physical results. 



1919] 



Pendleton : A Study of Soil Type 



65ol 



^H 



5H 



50ol 



45yo 



40^ 



35c/, 



30o/, 



^H 



2oy, 



'^-/o 



5ok 



Ooi 



\ 
















































































\\ 










































U 


















\ 






















l\ 




















\\ 




















1 




















1 


z'^V" 


^5_^ 


S.;-- 


^ 


\ 












6 






•... N 




^^ 


1^"" 











0J2.5 as I. Z. 4. a 16 32. 64. Gt-]\s. 
Size of Particles "^"^ 



Fig. 1. Graph showing the results of the Ililgard elutriator method of 
mechanical analysis on the four samples of Diablo clay adobe. 



University of California Publications in Agricultural Sciences [Vol. 3 



Mechanical Analysis 

Hilgard Elutrkitor Mctliod. — Tliat there is a wide variation be- 
tween the samples is apparent (figs. 1-4). In fact, there is about 
as wide a range of differences among the samples of the Hanford 



1 

1 




















li 


) 


















1! 


'1 


















Il 


\ 


















// 


] 


















/ 

V 


\ 


















/\ 


\ 


















\ 


\ 


















\ 


\ 1 




















\ 1 




















\1 










/ 










\i 




^^^-.^ 


^ — 


<:^ 


/' 




\ 
\ 
\ 


/ 
/ 




\ 


^ 








s 

s 




\ 





Fig. 2. 
mechanical 



Graph showing the results of the Hilgard elutriator method of 
analysis on the three samples of Altamont clay loam. 



fine sandy loam and among those of the San Joaquin sand.y loam as 
between the two types. The most outstanding differences are where 
they ought to be, to show the differences that the type names presup- 
pose, i.e., in the "coarse sand" (64 mm.) and the "grits." The sam- 
ples of the San Joaquin sandy loam average a larger proportion of 
each of these separates than do the Hanford fine sandy loam soils. 



1919] 



Pendleton: A Study of Soil Types 



In the Hanford, no. l-t is notably heavier than the others, as shown 
by its silt content, which is nearly half again as great as that of the 
next highest sample. 

The gravel content (sizes above 2 mm.) is interesting in its uni- 
formity. In the San Joaquin soils the two samples above 1% are 



40o/, 




:\ay 0.25 0.5 / 2. 4 8 16 32 64- Grits 

Size of Particles mm 

Fig. 3. Graph showing the results of the HilgarJ elutriator method of 
mechanical analysis on the eight samples of San Joaquin sandy loam. 



nos. 11 and 26. The material in the latter soil is composed almost 
wholly of iron concretions, leaving sample no. 11 as the only soil with 
more than 1% actual gravel. In the Hanford samples none were 
found to have more than 1.5% gravel. 

The Hilgard method does not include any precise subdivision of 
the soils into groups or classes according to texture. Dr. Hilgard was 
not in favor of making the tine distinctions in texture that other 



382 



University of California Publications in Agricultural Sciences [Vol. 3 



investigators have emphasized. But if there were such a scheme, 
similar to that which the Bureau of Soils uses,"" it would be an easy 
matter to compare the results obtained through the use of the elutri- 
ator, and determine whether or not the soils examined belong to a 
given class. The simple comparison of the quantities, in different 



40% 




0.Z5' 0.5 1.0 2.0 4.0 8.0 16. 52. 64-. Grits. 
Size of Particles. mm. 

Fig. 4. Graph showing the results of the Hilgard elutriator method of 
mechanical analysis on the nine samples of Ilanford fine sandy loam. 



samples, of any given separate or separates is not absolute. For it 
must be realized that the conception of a soil class includes a certain 
range in the quantities of particles of the various sizes. This must 
be so since soils are ordinaril.y grouped into but ten or twelve class 
textures, while there exist among soils those with all gradations in 
the quantities of particles of the various sizes. 



26 Instructions to Field Parties, V. S. Bur. Soils, Bull. 1914, p. 
Bull. 85 (1912), p. 28. 



1919] Pendleton: A Study of Soil Types 383 

And because the ranges in the sizes of the soil particles separated 
by the Bureau of Soils method cut across those of the Hilgard 
metliod, it is impossible to regroup the results so that the Bureau of 
Soils grouping into textures may be applied. But without any such 
scheme, desirable as it may be, it has been pointed out that there is 
clearly apparent a rather wide variation in the analyses of the several 
samples of a type. All the soils representative of a given type are by 
no means closelv similar to one another. 



Table 1 — Comparison or Textures 



Texture as judged in the field 

*1 Diablo clay adobe 

2 Diablo clay adobe 

3 Altamont clay loam 

4 Altamont clay loam 

5 Diablo clay adobe 

6 Diablo clay adobe 

7 Altamont clay loam 

10 San Joaquin sandy loam 

11 San Joaquin sandy loam 

12 Sau Joaquin sandy loam 

13 San Joaquin sandy loam 

14 Hanford fine sandy loam 
1.5 Hanford fine sandy loam 

16 Hanford fine sandy loam 

17 San Joaquin sandy loam 

18 San Joaquin sandy loam 

19 Hanford fine sandy loam 

20 Hanford fine sandy loam 

21 Hanford fine sandy loam 

22 Hanford fine sandy loam 

23 Hanford fine sandy loam 

24 Hanford fine sandy loam 

25 Hanford fine sandy loam 

26 San Joaquin sandy loam 



Texture determined by 
mechanical analysis 

Clay 

Clay 
*Silty clay 

Clay loam (sandy) 

Clay 

Clay 

Clay loam (heavy) 
*Fine sandy loam 

Sandy loam (heavy) 
*Fine sandy loam 
"Fine sandy loam (heavy) 

Fine sandy loam (loam) 

Fine sandy loam 
* Sandy loam 

Sandy loam 

Sandy loam 
*Sandy loam (heavy) 

Fine sandy loam 

Sandy loam 

Fine sandy loam 

Fine sandy loam 

Fine sandy loam 

Fine sandy loam 

Sandv loam 



Note. — Textu 



ot judged correctly in the field. 



Mechamcal Analysis by the Bureau of Soils Method. — Among the 
other determinations made by the Division of Soil Technology on the 
surface horizons of the twent.y-four soils used in this investigation 
was that of making the mechanical analysis. The tables show the 
percentages of the several separates. In all cases the figures represent 
averages of duplicate determinations and in some cases the averages 
of quadruplicate determinations. With this method, as well as with 
the Hilgard elutriator, there are shown wide variations between the 



384 University of California Publications in Agricultural Sciences [Vol. 3 



60.Ct 




.005 .005 .05 .10 .25 .6 1.0 

mm. -.05 -.10 -.£5 -.5 -1.0 -2.0 
mtn, mm. mm. mm. mm. mm. 

Fig. 5. Graph showing the results of the Bureau of Soils method of 
mechanical analysis on the four samples of Diablo clay adobe. 



1919] 



Pendleton: A SUidy of Soil Types 



samples of a given type. But the graphs of the percentages (figs. 
5-8), determined by the Bureau of Soils method for the several types 
are not as closely similar as the graphs of the elutriator results for 
the same types. That is, using the Bureau of Soils method, the graph 
of the Hanford fine sandy loam does not resemble that of the San 
Joaquin sandy loam as much as do the graphs of the results made 




.00.', .005-.05 .03-. 10 .10-. 25 .25-..5 .5-1.0 1.-2. 

Fig. 6. Graph showing the results of the Bureau of Soils method of 
mechanical analysis on the three samples of Altamont clay loam. 



upon the same soils by the Hilgard elutriator method. This would 
lead one to believe that the Bureau of Soils method of mechanical 
analysis is the better suited for separating soils into groups ; even 
though these soils which were classified in the field according to the 
differences which are the more prominent would be expected to show 
greater differentiations when examined by the Bureau of Soils labora- 
tory methods. 



386 University of California Publications in Agricultural Sciences [Vol. 3 

Comparison of Textures. — Table 1 gives tlie texture as shown on 
the soil survey map of the localitj^ as well as the results of the labora- 
tory check. This texture as given on the map was also judged by me 




.005 .005 .05 .10 .25 
-.05 -.10 -25 -.5 
Size of Particles. 



.5 

-.10 



-2.0 mm. 



Fig. 7. Graph showing the results of the Bureau of Soils method of 
mechanical analysis on the eight samples of San Joaquin sandy loam. 



in the field to be more or less true to the type as mapped. I say more 
or less true, for the field notes, as given in appendix B, show that in 
several eases I was unable to obtain in the localitj- what I believed to 



1919] 



Pendleton: A Study of Soil Types 



be a sample of the soil thoroughly tj'pical of the class and type in 
question. Sample no. 3 had a large lime content which I thought 
might more or less obscure the texture. "Slightly heavj^ and barely 
enough sand for a sandy loam" is the comment on sample 12, while 
"a heavy sand.y loam, approaching a loam" is found in the notes on 
sample 13. The second column of the table shows the class sub- 
divisions into which the soils were placed according to the mechanical 
analj^sis. The words in parenthesis show modifying conditions but 
do not indicate a change in the class. In considering the class groups 
such as sandy loam, fine sandy loam, etc., it should be remembered 
that though the groups are rather broad, the limits are arbitrary 
and quite sharp. So the results of a mechanical analysis may place 
a soil in the sandy loam class if 25% or more is fine gravel, coarse and 
medium sand, while if less than 25% be present the soil belongs to the 
fine sandy loam class, providing at the same time the amounts of silt, 
clay, and fine sand are within the specified limits. The two soils may 
be a great deal alike in texture though placed in different classes. 
The failure of my judgment regarding the texture shows one of the 
difficulties that the field man is continually facing. And his failure 
to judge textures correctly is one of the causes of criticism of soil 
survey work. 



Table 2 — Mechanical Analyses, Hilgabd Elutmatob 
Diablo Clay Adobe 
Separates 



' 


Diameter, 


Velocity, 
mm. per 
second 




Oiim^ 


pica 




Name 


l-A 

% 


2-A 

% 


5-A 

% 


6-A 

% 


Clay 


.01 


0.25 


44.16 


35.81 


44,97 


64.63 


Fine silt 


,01 -.016 


0.2o 


23.91 


34.08 


2.5.57 


25.13 


Medium silt 


.016-025 


0.5 


5.97 


7,37 


4.14 


1.03 




.02.5-036 


1 


8.10 


9.09 


5.28 


1.83 


Coarse silt 


.036-.047 


2 


7.77 


7.47 


5.45 


1.99 




.047-.072 


4 


6.05 


4.09 


6.18 


2.13 


Fine sand 


.072-.12 


8 


3.28 


1.33 


5.81 


2.07 




.12 -.16 


16 


0.48 


0.43 


1.73 


0.90 


Medium sand 


.16 -.30 


32 


0.08 


0.21 


0.38 


0.21 


Coarse sand 


.30 -..50 


64 


0.18 


0.11 


0.49 


0.11 


Total weight 


of separates, gm. 




19.18 


19.62 


19.30 


19.68 


Weight of original sample, gm. 




18.83 


18.88 


18.66 


18.16 


Grits, % 


0..5-2'.0 mm. 




0.26 


0.29 


0.57 


0.10 


Hygroscopic 


moisture, % 




6.20 


5.93 


7.18 


10.12 



388 University of California Publications in Agricultural Sciences [Vol. 3 




.005 .005 .05 -"^ 25 .5 1.0 mm 

-.05^ -.1.0 -.25 -5 -1.0 2.0 mm. 

Size of Particles 
Fig. 8. Graph showing the results of the Bureau of Soils method of 
mechanical analysis on the nine samples of Hanford fine sandy loam. 



1919] 



Pendleton: A Study of Soil Types 



Table 3 — Mechanical Analyses, Hilgard Elutmator Method 
Allamont Clay Loam 
Separates 





Diameter 


Velocity 
mm. per 
second 




otimpuro 




Name 


3-A 

% 


4-A 

% 


7-A 
% 


Clay 


.01 


0.25 


28.48 


26.41 


22.65 


Fine silt 


01 -.016 


0.25 


43.42 


17.73 


41.18 


Medium silt 


016-.02.1 


0.5 


2.96 


2.39 


4.67 




02.5-.036 


1 


4.37 


4.82 


8.51 


Coarse silt 


036-.047 


2 


4.95 


4.89 


6.01 




047-.072 


4 


5.52 


7.52 


7.90 


Pine sand 


072-.12 


8 


5.14 


8.83 


5.5-^ 




12 -.16 


16 


3.89 


13.61 


1.98 


Medium sand 


16 -.30 


32 


0.88 


10.40 


0.95 


Coarse sand 


30 -..50 


64 


0.21 


3.39 


0.61 


Total weights ol 


separates, 


gm. 


18.71 


19..54 


20.96 


AVeight of origii 


lal sample, 


gm. 


18.50 


19.16 


19.21 


Grits, % 0.5- 


2.0 mm. 




3.98 


8.09 


1.63 


ITygroscopic nioi 


sture, % 




8.08 


4.37 


4.09 



Table 4 — Mechanical Analyses, Hilgard Elutriator 
San Joaquin Sandy Loam 





Diameter 


Velocity, 

per 
secoud 








Samp 


es 








Name 


10-.\ 

% 


11-A 

% 


12-A 


13-A 


17-A 


18-A 

% 


21-A 


26-A 

% 


Clay 


.01 


0.25 


11.14 


15.46 


8.99 


10.75 


10.53 


8.72 


8.35 


16.64 


Fine silt 


01 -.016 


0.25 


20.24 


31.88 


26.57 


24.04 


16.20 


18.56 


14.73 


20.78 


Medium 






















silt 


.016-.025 


0.5 


1.44 


2.73 


2.31 


4.64 


1.81 


3.06 


3.54 


3.83 




.025-036 


1 


6.54 


9.11 


1.33 


9.86 


5.89 


6.93 


6.98 


9.24 


Coarse silt 


.036-.047 


2 


8.36 


10.23 


1.19 


9.59 


5.82 


6.90 


7.10 


7.09 




.047-.072 


4 


9.50 


8.41 


10.14 


10.05 


8.46 


8.45 


7.67 


8.89 


Fine sand 


.072-12 


8 


10.66 


7.47 


10.72 


10.92 


12.04 


9.72 


12.86 


5.77 




.12 -.16 


16 


10.30 


5.97 


10.88 


16.14 


13.43 


10.56 


13.53 


3.85 


Medium 






















sand 


.16 -.30 


32 


14.69 


6.91 


11.75 


1.96 


19.21 


16.59 


13.05 


0.86 


Coarse sand 


.30 -.50 


64 


7.11 


1.32 


3.54 


2.12 


6.00 


10.50 


12.14 


23.04 


Total weight of separa 


tes, gm. 


20.02' 


20.44 


19.99 


20.10 


20.38 


20.06 


20.33 


20.14 


Weight of original sam 


pie, gm. 


19.80 


19.51 


19.72 


19.76 


19.85 


19.86 


19.85 


19.69 


Grits, % 


0.5-2.0 mm. 


16.70 


23.54 


8.84 


8.10 


23.12 


32.00 


28.50 


36.00 


Hygroscopic 


moisture 


% 


0.98 


2.48 


1.38 


1.22 


0.75 


0.70 


0.75 


1.57 


Note. — All weighings 


made on 


the water free basis. 













University of California Publications in Agricultural Sciences [Vol. 3 

Table a — Mechanical Analyses, Hilgard Elutriator Method 
Hanford Fine Sandy Loam 





Velocity, 
mm. 
Diameter per 
mm. second 








S 


amples 










Name 


14- A 

% 


15-A 

% 


16-A 


19-A 


20- A 

% 


22-A 

% 


23-A 

% 


24-A 

% 


25-A 
% 


Clay 


.01 


0.25 


12.89 


8.16 


11.97 


11.09 


10.55 


7.97 


8.68 


6.47 


6.65 


Fine silt 


.01 -.016 


0.25 


37.25 


19.39 


24.61 


5.95 


22.09 


14.15 


22.57 


11.11 


14.54 


Medium silt 


.016-02.5 
.025-.036 


0.5 
1 


4.19 
8.63 


3.05 
5.04 


3.22 
5.06 


1.67 
5.27 


6.40 
8.40 


3.15 
5.29 


.5.90 
6.89 


1.20 
5.08 


1.59 
6.36 


Coarse silt 


.036-.047 
.047-.072 


4 


7.95 
6.23 


6.57 
10.23 


5.99 


7.14 
12.76 


7.68 
9.93 


6.47 
11.30 


10.53 
13.03 


7.48 
13.91 


7.91 
12.64 


Fine sand 


.072-.12 


8 


5.26 


12.31 


8.57 


17.79 


10.48 


17.15 


12.71 


19.27 


18.11 




.12 -.16 


16 


7.15 


13.93 


9.76 


12.00 


12.29 


17.39 


7.94 


21.56 


9.55 


Medium sand 


.16- ..30 


32 


8.81 


1.5.29 


16.05 


24.20 


10.03 


14.87 


9.88 


12.36 


19.15 


Coarse sand 


.30- .50 


64 


1.43 


6.02' 


7.51 


2.13 


2.70 


2.27 


1.85 


1.50 


3.50 


Total weight of separates, gm. 
Weight of original sample, gm. 
Grits, % 0.5-2.0 


20.19 

19.46 

4.12 


20.23 
19.90 
13.23 


20.53 
19.69 

25.47 


20.08 

19.82 

7.85 


20.27 

19.73 

6.71 


20.06 

19.81 

3.07 


20.30 

19.78 

7.24 


20.26 
19.83 

6.85 


19.18 

19.78 

3.83 


Hygroseoiiie 


moisture, 


% 


2.73 


0.49 


1..54 


0.89 


1.34 


0.94 


1.10 


0.84 


1.10 



Table 6 — Mechanical Analyses, Bureau of Soils Method 
Diablo Clay Adobe 



Name 


Diameter 


1-A 


2-A 

% 


5-A 

% 


6-A 


Clay 


.005 


44.81 


44.44 


45.67 


56.01 


Silt 


.005- .05 


32.00 


42.51 


23.01 


14.28 


Very fine sand 


.05 - .10 


19.61 


11.35 


21.58 


25.58 


Fine sand 


.10 - .25 


1.36 


1.33 


4.81 


2.10 


Medium sand 


.25 - .5 


0.26 


0.69 


0.95 


2.05 


Coarse sand 


.5 -1.0 


0.58 


0.20 


1.56 


0.00 


Fine gravel 


1.0 -2.0 


0.03 


0.02 


0.04 


0.00 


rE. — Determination 


s made by the 


DiTi,sion oi 


' Soil Technology. 





Table 7 — Mechanical Analyses, Bureau of Soils Method 
Altamont Clay Loam 



Name 


Diameter 


3-A 


4-A 


7-A 
% 


Clay 


.005 


33.19 


26.50 


31.84 


Silt 


.005- .05 


31.76 


17.35 


37.40 


Very fine sand 


.05 - .10 


22.81 


39.15 


24.70 


Fine sand 


.10 - .25 


8.97 


6.08 


3.27 


Medium sand 


.25 - .5 


1.99 


7.78 


■ 0.92 


Coarse sand 


.5 -1.0 


1.74 


3.06 


0.55 


Fine gravel 


1.0 -2.0 


1.01 


1.22 


0.22 



Note. — Determinations made by the Divi 



of Soil Technology. 



1919] Pendleton: A Study of Soil Types 

Table 8 — Mechanical Analyses, Bureau of Soils Method 
San Joaquin Sa7idy Loam 
Separates Samples 



Name 


Diameter 


10- A 


11-A 


12-A 

% 


13-A 
% 


17-A 

% 


18-A 

% 


21-A 


26-A 

% 


Clay 


.005 


10.78 


15.77 


16.16 


16.94 


11.77 


10.49 


8.28 


17.38 


Silt 


.003- .0.5 


21.60 


35.97 


25.04 


22.70 


15.97 


26.74 


17.70 


18.17 


Very fine sand 


.05 - .10 


28.07 


18.53 


27.42 


47.01 


20.42 


12.02' 


15.92 


13.84 


Fine sand 


.10 - .25 


19.96 


2.66 


17.07 


3.99 


22.57 


16.61 


21.27 


10.26 


Medium sand 


.25 - .5 


9.20 


6.96 


5.80 


4.69 


10.75 


13.85 


13.57 


14.72 


Coarse sand 


.5 -1.0 


9.08 


8.51 


6.52 


2.96 


13.81 


16.52 


21.41 


24.26 


Fine gravel 


1.0 -2.0 


1.34 


12.52' 


2.15 


1.81 


3.13 


4.07 


2.07 


2.02 


Note. — Determ: 


inations made 


by the Division of 


Soil Tecl 


inology. 











Table 9 — Mechanical Analyses, Bureau of Soils Method 
Hanford Fine Sandy Loam 



Separates 










Samples 










Diameter 


14 jA 


15-A 

% 


16-A 

% 


19-A 


20-A 

% 


22-A 

7c 


23-A 

7c 


2 4- A 


25-A 

% 


Clay .005 


14.10 


12.08 


16.84 


15.28 


15.95 


7.79 


10.61 


9.83 


7.60 


Silt .00.5- .05 


39.25 


22.42 


16.16 


15.03 


32.90 


22.70 


24.38 


11.42 


12.90 


Very fine sand .05 - .10 


22.66 


37.12 


16.46 


32.87 


22.58 


36.15 


38.73 


42.05 


67.37 


Fine sand .10 - .25 


17. .54 


6.51 


17.32 


8.13 


18.20 


27.78 


16.51 


28.73 


5.88 


Medium sand .25 - .5 


4.71 


11.40 


11.70 


15.42 


4.97 


4.21 


4.66 


4.27 


3.47 


Coarse sand .5 -1.0 


1.99 


8.49 


1.5.54 


9.27 


3.07 


1.47 


3.28 


3.01 


1.27 


Fine gravel 1.0 -2.0 


0.13 


1.91 


5.27 


3.63 


0.20 


0.20 


1.48 


1.02 


1.02; 


Note. — Determinations made 


by the D 


ivision , 


3f Soil Technology. 











Maisturc Equivalent. — The moisture equivalents of the surface 
horizon samples were determined by the Division of Soil Technology 
(table 10, and figs. 9, 10). The different types gave quite distinct 
averages, though there was considerable variation within the type. 
The Diablo clay adobe varied from 37% to 57%, with an average of 
47%,. The Altamont clay loam varied from 22% to 37%), with 28% 
as an average. The San Joaquin sandy loam varied from 7% to 
15%, with the average of 11%. The Hanford fine sandy loam varied 
from 11% to 25%, with 15% as the average. These figures show 
that as a whole the moisture equivalents of the several types are 
distinct, though there is the usual overlapping in some cases. The 
samples of a given type are in many instances closely similar, though 
not always or even usually so. 



Vniversity of California Publications in Agricultural Sciences [Vol. 3 







1 






/ 




/ 


' 




/ 






/ 




























\ 
\ 
\ 
\ 


y 

/ 
/ 

/ 

















\ 




\ 




\ 




^ 


-^ 


\ 
\ 




\ 

\ 

\ 

\ 




\ 

\ 


^^- 







Fig. 9. Graph showing the results of the determination of the moisture 
equivalent and of the hygroscopic coefficient on the four samples of Diablo 
clay adobe and the three samples of Altamont clay loam. 



1919] 



Pendleton: A Study of Soil Types 



Table 10 — Moisture Equivalent 



Diablo Clay 


Adobe 


Altaraont Clay Loam 


.San 


Joaquin 
Loam 


Sandy 


Hanfo 


rd Fine 
Loam 


Sandy 


No. 


% 


Average 
% 


Average 

No. % % 


No. 


% 


Average 


No. 


% 


Average 


1-A 


49.70 




3-A 38.10 


10-A 


10.30 




14-A 


25.80 






48.90 


49.30 


37.80 37.95 




10.10 


10.20 




25.20 


25.50 


2-A 


37.40 




4-A 23.41 


11-A 


15.52 




1.5- A 


11.50 






36.80 


37.10 


22.35 22.88 




15.54 


15.53 




11.20 


11.35 


5-A 


46.55 




7-A 23.90 


12-A 


13.72 




16-A 


1.5.60 






48.10 


47.32 


23.90 23.90 




i;:.62 


13.67 




15.60 


15.60 


6-A 


58.80 




Average 28.94 


13-A 


14.50 




19- A 


13.30 






56.80 


57.80 






14.60 


14.55 




14.30 


13.80 


Average 


! 47.88 




17-A 


8.90 




20- A 


18.41 














8.98 


8.94 




18.38 


18.39 










18-A 


7.92 

7.87 


7.89 


22-A 


12.73 
12.22 


12.47 










21-A 


7.16 
7.09 


7.12 


23-A 


11.08 
10 90 


10.99 










26-A 


11.30 
11.81 


11.55 


24-A 


16.30 
16.17 


16.23 










Average 


11.18 


25-A 


11.17 




















12.72 


11.94 
















Average 


15.14 


Note. — Determinatic 


)ns made by the Divisior 


1 of Soil 


Technology. 









Table 11 — Hygroscopic CoEFnciENT 



Diablo Clay 


Adobe 


Altan 


lont Cla^ 


• Loam 


San J 


'oaquin 
Loam 


Sandy 


Hanfoi 


■d Fine 
Loam 


Sandy 


No. 


% 


Average 

% 


No. 


r.„ ■ 


Average 


No. 


% 


Average 

% 


No. 


"', ' 


.A, verage 

% 


1-A 


15.88 




3-A 


17.48 




14-A 


5.35 




10-A 


2.46 






1.5.08 


15.48 




18.45 


17,93 




4.70 


5.03 




2.51 


2.49 


2-A 


9.90 




4-A 


9.60 




15-A 


1.31 




11-A 


3.44 






9.48 


9.09 




7.00 


8.30 




1.39 


1.35 




3.45 


3.44 


5-A 


14.18 




7-A 


7.92 




16-A 


3.90 




12-A 


3.58 






13.90 


14.04 




5.92 


6.92 




3.60 


3.75 




3.45 


3.52 


6-A 


15.20 




A 


verage 


1105 


19-A 


1.66 




13-A 


2,50 






15.70 


15.45 










1.80 


1.73 




2.60 


2.55 


Average 


! 13.66 








20-A 


2.90 




17-A 


1.84 


















3.02 


2.96 




1.62 


1.73 














22-A 


2.48 
2.89 


2.69 


18-A 


2.10 
2.00 


2.05 














23-A 


2.38 
2.53 


2.46 


21-A 


1.98 
1.92 


1.95 














24-A 


2.39 




26-A 


3.57 
















24-A 


2.39 






3.52 


3..55 
















2.37 


2.38 


Average 


2.66 














2.5-A 


1.78 
1.84 


1.81 









Note. — Determinatit 



nade by the Dr 



of Soil Technology. 



394 University of California Puilications in Agricultural Sciences [Vol. 3 

% 







-- 












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y 










■— -~_^ 


— -_ 








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y 






\ 






\ 










^ 




/ 


\ 




















^ 

^ 


"^- 


-"-" 















11 IT) 16 10 20 22 23 24 2o Soils 

Fig. 10. Graph showing the results of the determination of the moisture 
equivalent and of the hygroscopic coefficient on the eight samples of San 
Joaquin sandy loam and the nine samples of Hanford fine sandy loam. 



Hiigroscopic Cocfficirnt. — The determination of this coefficient, 
also by the Division of Soil Technology, shows no very distinct values 
for the several types under consideration (table 11, figs. 9,10). The 
Diablo clay adobe samples vary from 9.6% to 15.4%, with the average 
of 13.67c'- The Altamont clay loam samples vary from 6.9% to 
17.9%, averaging 11%. The S.an Joaquin sandy loam varies from 



1919] Pendleton: A Study of Soil Types 395 

1.7% to 3.5%, with the average of 2.66%, while the Hanford fine 
sandy loam varies from 1.3% to 5%, with the average of 2.68%. 
There is no question that here the range of values within every type 
is greater than that from type to type. Even excluding those sam- 
ples shown by the mechanical analysis to be not true to name there 
is a wide range within each type — a range too wide to allow one 
to answer the question of this paper in the affirmative. 



2 5 6 Soils 

Graph sliowing the percentages of nitrogen and of phosphorus in 



Fig. 11 
the four samples of Diablo clay adobe. 



The Chemical Data 
Total Nitrogen 

Diablo claij adohc. — There is more variation in nitrogen content 
between the different representatives of the type than one would 
expect from a visual examination of the soils (table 12 and fig. 11). 
No. 2 would be expected to contain less nitrogen than no. 5 because of 
the lighter color, but such is not the case. In the A horizon, no. 5 
shows the lowest notal nitrogen content with 0.084%, no. 2 is higher 
with 0.092%,, no. 1 with 0.104%, and no. 6 is the highest with 0.117%. 
The decrease in the nitrogen content with the increase in depth is 
normal. In the C horizon, no. 1 has the lowest total nitrogen content 
with 0.057%, and no. 6 the highest, with 0.078%,. 

AUamont clay loam. — The agreement between the A samples is 
fairly close (table 13, and fig. 12). No. 4 ha.s 0.1037o, no. 7, 0.104%, 
and no. 3 has 0.123%. This gives an average for the surface soil of 
0.110%, as compared with 0.099% in the Diablo clay adobe. It is to 
be noted that the nitrogen content of the subsoil is relatively less 
than that in the Diablo subsoils, 0.071% and 0.056% in the Altamont 
B and C horizons, respectively, as against 0.076% and 0.065% in the 



396 University of California Publications in Agricultural Sciences [Vol. 3 

B and C horizons of the Diablo. The average amount of nitrogen is 
higher in the A horizon of the Altamont tlian in the Diablo, eontrarj- 
to what one would expect from the color of the soils, since the Alta- 
mont is typically a brown soil and the Diablo a dark gray to black soil. 
San Joaquin sandy loam. — The nitrogen content of these soils is 
uniformly low (table 14 and fig. 13). from 0.037c to 0.05%, and i.s but a 
third to a half of what Hilgard believed adequate for crop production. 




Fig. 12. Graph showing the percentages of nitrogen and of phosphorus in 
the three samples of Altamont clay loam. 




Fig. 13. Graph showing the percentages of nitrogen and of phosphorus in 
the eight samples of San-Joaquin sandy loam. 



The nitrogen content is seen to vary more or less directly with the 
amount of the finer sediments present in the soil — nos. 11 and 12 
being heavy members of the type, with 0.05% and 0.047% respec- 
tively, and nos. 17 and 18 light members of the type with 0.029% and 
0.027% respectively. It may be noted that the nitrogen content of 
the various horizons are not as far apart as in the other types. The 
averages for the three horizons are: A — 0.037%, B — 0.027%, and 
C — 0.026%. It must be borne in mind that the San Joaquin sandy 
loam horizons are not full 12-incli samples, and that the total depth 
of the sami^ling is less. 



1919] 



Pendleton : A Study of Soil Types 



Hanford fine sandy loam. — Here again in the A horizon tlie nitro- 
gen content is fairly uniform (table 15, and fig. 14), with from 0.045% 
to 0.072%, if the extra typical no. 14, with 0.119%, be left out of 
consideration. One would suppose these soils to be higher in their 

































/ 
















/ 
















/ 
















/ 


^ 








/ 


\ 






\ 




^^ 


\ 


/ 


^ 






\ 





















~ 


— —- ' 





— ■ 


-— -_. 






Fig. 14. Graph showing the percentages of nitrogen and of phosphorus in 
the nine samples of Hanford fine sandy loam. 



nitrogen content, as compared with the San Joaquin series, than the 
results show. The B and C horizons of the Hanford samples contain 
0.038% and 0.028% nitrogen, respectively, showing that with the 
increase of depth there is a more rapid decrease of nitrogen than in 
the San Joaquin samples, with the nitrogen content of the C horizon 
of the Hanford only 0.002% above that of the C horizon of the San 



398 University of California Publications in Agricultural Sciences [Vol. 3 

Joaquin. The greenhouse pot cultures showed the effect of the much 
higher nitrogen content in no. 14 in giving better color and growth 
to the plants and especially to the grains. The increase of the nitrogen 
in the surface of no. 23, as compared with the B and C horizons, 
might be ascribed to the fertilizers applied to the orange grove where 
this sample was collected; yet no. 24 is a truck soil which has been 
fertilized to a considerable extent with barnyard manure. The nitro- 
gen content of this type, as judged by the previous standards, is 
quite inadequate. 

Compare the nitrogen content of the A horizons of the four types : 
The Diablo has an average of 0.099%, with a range or from 0.084% 
to 0.117% ; the Altamont has an average of 0.110%, with a range of 
from 0.103% to 0.123% ; the San Joaquin has an average of 0.037%, 
with a range of from 0.027% to 0.050%; and the Hanford has an 
average of 0.062%., with a range of from 0.045% to 0.119%>. Thus 
the total nitrogen content of the several types is reasonably constant 
within the type and rather distinct for the types. 



Table 12 — Total Nitrogen 
Diablo Clay Adobe 







Horizon 






A 


Average 
% 


B Average 

% % 


C 

% 


Average 

% 


0.109 


0.105 


0.076 0.069 


0.056 


0.057 


0.101 




0.063 


0.059 




0.100 




0.072 


0.062 




0.084 


0.092 


0.064 0.068 


0.058 


0.060 


0.085 




0.065 


No sample 


0.084 


0.084 


0.065 0.065 






0.114 




0.097 


0.075 




0.122 


0.118 


0.107 0.102 


0.083 


0.079 




0.100 


0.076 




0.065 



Table 13 — Total Nitrogen 
Altamont Clay Loam 



Hor 



Sample 


A 


Average 


B 

% 


Average 

% 


C 

% 


Averag( 
% 


3 


0.123 




0.089 




0.069 






0.124 


0.123 


0.087 


0.088 


0.067 


0.068 


4 


0.103 




0.054 




0.041 


0.041 




0.103 


0.103 


0.053 


0.053 


0.041 


0.041 


7 


0.106 




0.070 




0.061 






0.104 


0.105 


0.077 


0.073 


0.059 


0.060 


Avsra; 


je 


0.110 




0.071 




0.056 



1919] Pendleton: A Study of Soil Types 

Table 14 — Total Nitrogen 
Sati Joaquin Sandy Loam 



Sample 


A 

Vc 


Average 


B 


10 


0.037 




0.026 




0.038 


0.037 


0.029 


11 


0.0.51 




0.042 




0.0.51 


0.051 


0.046 


12 


0.049 




0.032 




0.045 


0.047 


0.034 


13 


0.040 




0.038 




0.040 


0.040 


0.043 


17 


0.028 




0.019 




0.030 


0.029 


0.018 


18 


0.028 




0.016 






0.028 


0.017 


21 


0.029 




0.012 




0.030 


0.029 


0.012 


26 


0.041 




0.026 




0.041 


0.041 


0.027 


Averaj 


;e 


0.038 





Sample 


% 


14 


0.113 




0.126 


15 


0.052 




0.055 


16 


0.058 




0.054 


19 


0.046 




0.044 


20 


0.062 




0.058 


22 


0.057 




0.061 


23 


0.075 




0.071 


24 


0.050 


25 


0.045 



Table 15 — Total Nitrogen 
Hanford Fine Sandy Loam 



c 

% 


Average 

% 


0.022 




0.020 


0.021 


0.038 




0.040 


0.039 


0.042 




0.040 


0.041 


0.033 




0.033 


0.033 


No sample 


0.018 




0.021 


0.019 


0.014 




0.014 


0.014 


0.016 





Average 



Horizon 






B 

% 


Average 

% 


C 

% 


Average 

% 


0.084 




0.060 




0.081 


0.082 


0.057 


0.058 


0.039 




0.028 




0.043 


0.041 


0.027 


0.028 


0.030 




0.020 






0.030 


0.023 


0.021 


0.025 




0.024 


0.023 


0.025 


0.025 


0.023 


0.023 


0.032 




0.024 




0.034 


0.033 


0.022 


0.023 


0.033 




0.025 




0.036 


0.034 


0.023 


0.024 


0.028 




0.020 




0.030 


0.029 


0.016 


0.018 


0.032 


0.034 


0.028 


0.028 


0.031 




0.022 




0.032 


0.031 


0.024 


0.023 




0.038 




0.027 



rniversity of California Publications in Agricultural Sciences [Vol. 3 



DuMo clay adohe. — The variations in the humus content of the A 
samples (table 16, and fig. 15) are moderate, 1.1% to 1.4%, while the 
B and C horizons do not agree so closelv with each other or with the 













/ 

/ 

/ 












/ 
/ 

/ 










/ 
/ 
/ 














\ 
^^^ 


/ 


























/ 












/ 
/ 


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— xl^ 




/ 


-^ 






x. 


■ -^ 

\ "^ 


/ 










\ 
\ 


.-■-■' 


-■■ 



Loss on 
Ignition 






CaO 

12 5 Soils 

Fig. 15. Graph showing the loss on ignition, the amount of humus, and 
the percentages of calcium, magnesium, and potassium in the four samples 
of Diablo clay adobe. 



surface foot. The average content of humus in the A samples is 
1.26%,, in the B samples 0.95%, and in the C samples 0.75%. It is 
worthy of note that soil no. 2, with the lightest color of the four, and 
what might be supposed to be a lower humus content, has next to the 
highest amount. 



1919] 



Pendleton: A Study of Soil Types 



Altamont clay loam. — Here tlie variations in the humus content 
(table 17, and fig. 16) are small in the A horizon, 1.1% to 1.3%. The 
average is 1.24%. The B and C samples show a good parallelism 
among themselves, but not so good when compared with the surface. 
The average of the B horizon is 0.84%, and of the C horizon 0.57%. 




3 4 7 Soils 

Fig. 16. Graph showing the loss on ignition, the amount of hunuis, and the 
percentages of calcium, magnesium, and jiotassium in the three samples of Alta- 
mont clay loam. 



San Joaquin sandy loam. — This type contains a considerable quan- 
tity of humus (table 18, and fig. 17) when one takes into considera- 
tion the popular criteria for the presence of humus, for the red to 
reddish brown San Joaquin soils are very different from the brown 
Altamont or the black Diablo soils. The samples of this type gave 



402 University of California Publications in Agricultural Sciences [Vol. 3 

light colored or nearly colorless humus solutions. But when the ali- 
quots were ignited, after evaporation, there was a very noticeable 
blackening and charring of the residue, together with a considerable 



















/ 


^ 












/ 


\ 












/ 


\ 
\ 












/ 

/ 


\ 












/ 


\ 










/ 


/ / 


■■\\ 








/ 

/ 




/ 


H 








/ 
/ 


/ 




\ 
\ 




/ 


/ 

\ / 


/ 


/ 




\\ 




/ 


\/ 


/ 


/ 




\ 




/ 


\ 


/ 


/ 




V 




/ 


/ \ 




/ 




\ 






/ \ 




/ 




/ \ 


\— — 




/ 




'■ 






\ 
"\ 


"~~~- 


/ 


\ / 




/ 




\ 


\ 




/ \ 




/ 






\ 




/ 

/. ; 


■"V-=^'- 





"■■■-.,"^ 




\ 


■\ .••••■' 

V 


y^' 














/' 










^' 


^" 



Fig. 17. Graph showing the loss on ignition, the amount of humus, and 
the percentages of calcium, magnesium, and potassium in the nine samples of 
San Joaquin sandy loam. 



loss in weight. Tliis phenomenon, in the light of the work of Gortner,-^ 
shows that these soils have a ' ' humus ' ' content above that which they 
might be supposed to have, because of the almost complete absence of 



27 Soil Science, vol. 2 (1916), pp. 395^42. 



1919] Pendleton: A Study of Soil Tyi>cs 403 

the "black pigment." Soil no. 26, probably the only virgin soil in 
the series, shows a particularly high content of humus for such a soil, 
though from the color of the soil one would suspect but very little 
humus. The agreement between the three horizons of the San Joaquin 
sandy loam samples is close. The average content of humus was 
0.68% in the A, 0.51% in the B, and 0.38% in the C horizon. 

Hanford fine sandy loam. — ^The variations in humus content in this 
type are greater than in any of the others (table 19, and fig. 18). Tliis 
is possibly because of two factors : the open texture of the soil, hence 
the rapid loss of organic matter by oxidation processes ; and secondly, 
the high agricultural value of this soil, which has led to a greater appli- 
cation of fertilizers than has been the case with the other soils. The 
actual variations in the humus content are large, 0.7% to 2.1% with 
the average of 1.15% for horizon A, from 0.5% to 1.8% with the aver- 
age of 0.81%, for B, and from 0.44% to 1.07%' with the average of 
0.59% for C. The extra-typical sample no. 14 is above any of the 
others in the total humus content. The variations in the subsoil 
humus content are more or less parallel to those of the surface soil. 

The following averages of the humus content of horizon A, Diablo 
1.26%, Altamont 1.24%, San Joaquin 0.687o, Hanford 1.15%, show 
that there is not much difference between the soils, except for the San 
Joaquin sandy loam, which has an average of half the others. Within 
the type the soils may be nearly alike, as in the San Joaquin and Alta- 
mont, or may be variable to a large degree, as in the Hanford. The 
variations in the humus content of the soils are small, considering the 
diverse nature of the soils, and the usual methods for judging the 
quantity of humus. 









Table 16-- 


-Humus (and 


Humus Ash) 


















Diablo Clay Adobe 


















Humus 
Horizons 










Humus ash 
Horizons 






Sample 


A 


Average 


' ^. 


Average C 


Average 


A . 


Average 


B 


Average 


C 


Aver- 
age 


1 


l.OS 




0..51 




0.18 




0.55 




0.75 




0.45 






1.08 


l.OS 


0..51 


0.51 


0.24 


0,21 


0.56 


0.56 


0.73 


0.74 


0.46 


0.46 


2 


1.40 




1.16 




1.09 




1.01 




0.96 




1.09 






1.38 


1.39 


1.15 


1.15 


1.02 


1.06 


1.03 


1.02 


0.96 


0.96 


0.96 


1.03 


5 


1.17 




0.87 








1.08 




1.19 










1.12 


1.15 


0.91 


0.89 






1.10 


1.09 


1.14 


1.17 






6 


1.48 




1.26 




0:95 




0.98 




0.88 




0.78 






1.37 


1.43 


1.26 


1.26 


0.09 


0.97 


0.95 


0.96 


0.91 


0.90 


0.85 


0.81 


iverai 


?e 


1.26 




0.95 




0.72 




0.91 




0.95 




0.77 



404 University of CaJifornia Publications in Agricultural Sciences [Vol. 3 

% 




Fig. 18. Graph sliowing the loss on ignition, the amount of humus, and 
the percentages of calcium, magnesium, and potassium in the nine samples of 
Hanford fine sandy loam. 



1919] 



Pendleton: A Study of Soil Types 



Table 17 — Humus (and Humus Ash) 
Altamont Clay Loam 



A Average B Average C Average 

% % ■ '/o % % % 

1.06 0.S9 0.59 

1.13 1.09 0.84 0.86 0.58 0.59 



1.33 1.31 0.71 0.70 0.28 0.43 



1.31 1.32 0.96 0.96 0.68 0.68 



A Average 

% % 


B Average 

% % 


C 


Aver- 
age 


1.29 




1.08 




0.95 




1.23 


1.26 


1.28 


1.18 


0.95 


0.95 


0.80 




0.98 




0.91 




0.85 


0.83 


0.98 


0.98 


1.03 


0.97 


0.72 




0.87 




1.09 




0.75 


0.74 


0.88 


0.88 


1.08 


1.08 




0.94 




1.01 




1.00 



Table 18 — Humus (and Humus Ash) 
San Joaquin Sandy Loam 
Humus Humus ash 



Hor 



Sample 


A A 


verage 


B Average 


C 


Average 


A Average 


B Average 


C 


Aver- 
age 

9o 


10 


0.66 


0.66 


0.53 


0.53 


0.27 


0.27 


1.31 


1.31 


1.33 


1.33 


0.67 


0.67 


11 


0.75 




0.41 




0.37 




0.51 




0.66 




0.58 






0.71 


0.73 




0.41 




0.37 


0,69 


0,60 




0.66 




0.58 


12 


0.62 




0.49 




0.32 




0.88 




1.50 




0.80 






0.65 


0.64 




0.49 




0.32 


0.95 


0.91 




1.50 




0.80 


13 


0.75 




0.50 




0.35 




1.3S 




0.90 




1.02 






0.78 


0.77 




0.50 




0.35 


1.36 


1.37 




0.90 




1.02 


]7 


0.51 
0.51 


0.51 


0.38 


0.38 






0.53 
0.57 


0.55 


1.23 


1.23 






18 


0.56 




0.60 




0.42 




0.61 




0.76 




1.79 






0.60 


0.58 


0.58 


0.59 




0.42 


0.56 


0.59 


0.75 


0.76 




1.79 


21 


0.52 




0.19 




0.18 




0.53 




0.37 




0.37 






0.52 


0.52 


0.21 


0.40 


0.21 


0.19 


0.54 


0.53 


0.37 


0.37 


0.48 


0.42 


26 


1.04 




0.79 




0.68 




0.89 




3.57 




5.28 






1.01 


1.02 


0.79 


0.79 


0.82 


0.75 


0.76 


0.83 


3.63 


3.60 


5.46 


5.35 


Average 




0.66 




0.51 




0.38 




0.83 




1.24 




1.51 


Excludin 


^ no. 


26 
















0.95 




0.87 



Loss on Ignition 

The loss on ignition of the A horizon varies directly with the tex- 
ture of the soil, the heavier soils losing more on heating. Obviously 
the water of combination of the clay is a large factor in this loss. In 
the San Joaquin sandy loam the loss on ignition was determined in 
the three horizons. In the other three types the A horizon was the 
only one examined (tables 20, 21, and figs. 15-18). 



Vniversity of California Fuhlications in Agricultural Sciences [Vol.3 

Table 19 — Humus (and Humus Ash) 
Hanford Fine Sandy Loam 



Sample 


A 

% 


Average B 


Average C 


Average 


A Average 

% % 


B Average 

% % 


C 

% 


Aver- 
age 

% 


14 


2.11 




1.81 




1.10 




1.14 




1.24 




1.01 






2.09 


2.10 


1.78 


1.79 


1.05 


1.07 


1.17 


1.16 


1.27 


1.26 


1.09 


1.05 


15 


1.79 




0.8S 




1.04 




1.88 




0.94 




0.92 






1.77 


1.78 


0.93 


0.90 


0.67 


0.86 


1.85 


1.86 


0.89 


0.92 


0,91 


0.92 


16 


1.20 




0.73 




0.41 




0.91 




0.93 




0.90 






1.20 


1.20 


0.73 


0.73 


0.46 


0.44 


0.91 


0.91 


1.47 


0.93 


0.90 


0.90 


19 


0.73 




0.51 




0.45 




0.48 




0.57 




0.78 






0.74 


0.73 


0.50 


0.51 


0.55 


0.50 


0.47 


0.48 


0.58 


0.58 


0.76 


0.77 


20 


1.08 




0.86 




0.59 




0.52 




0.90 




0.79 






1.06 


1.07 


0.89 


0.88 


0.50 


0.55 


0.56 


0.54 


0.90 


0.90 


0.78 


0.78 


22 


0.96 




0.73 




0.58 




0.59 




0.60 




0.58 






0.96 


0.96 


0.71 


0.72 


0.56 


0.57 


0.59 


0.59 


0.60 


0.60 


0.63 


0.61 


23 


1.04 




0.59 




0.38 




0.58 




0.45 




0.39 






1.07 


1.05 


0.62 


0.61 


0.38 


0.38 


0.57 


0.58 


0.41 


0.43 


0.37 


0.38 


24 


0.73 




0.55 




0.56 




0.58 




0.69 




0.82 






0.73 


0.73 


0.61 


0.58 


0.51 


0.54 


0.56 


0.57 


0.69 


0.69 


0.80 


0.81 


25 


0.71 




0.58 




0.45 




0.57 




0.67 




0.74 






0.69 


0.70 


0.56 


0.57 


0.42 


0.44 


0.61 


0.59 


0.71 


0.69 


0.78 


0.76 


Average 




1.15 




0.82 




0.59 




0.81 




0.78 




0.78 



Diablo clay adobe. — The variation in these samples was from 
5.6% to 8.6%, with the average of 6.8%. The Altamont clay loam 
has a variation of from 5% to 8.7%, averaging 6.7%. The San Joa- 
quin sandy loam has a range of variation between 1.6% and 4.2%, 
with an average of 2.6%. The loss on ignition of the lower horizons 
increases over that of the surface, because of the increase in texture. 
The B horizon shows an average less of 3.9% and the C horizon of 
4.67%. The Hanford fine sandy loam range of variation in the loss 
on ignition is, excluding no. 14, from 2.2% to 3.9%, with an average 
of 3.4%. Thus the curve for this type is quite uniform, except for 
no. 14, which shows a loss of 6.9%). 

It is seen that the averages in the loss on ignition of the A horizons 
of the Diablo and Altamont soils are close, and high, 6.8% and 6.7% 
respectively. The averages of the San Joaquin and Hanford sam- 
ples, 2.6% and 3.4% respectively, are low and not widely separated. 
Since the values for the types overlap considerably, and the averages 
are not distinct, except between the light and heavy groups, there is 
no significant distinction between the four types by this determination. 



1919] 



Pendleton: A Study of Soil Types 



407 







Table 20 — Loss on Ignition 










(Surface horizon only) 








Diablo Clay Adobe 


Altamont Clay Loam 


Hanfoi 


rd Fine Sa 
Loam 


ndy 


% 


% 


% %' 




% 


% 


1-A 6.62 




3-A 8.74 


14-A 


6.90 




6.66 


6.64 


8.82 8.78 




6.95 


6.92 


2-A 6..57 




4-A 5.05 


15-A 


2.27 




6.64 


6.60 


5.05 5.05 




2.30 


2.28 


5-A 5.61 




7-A 6.58 


16-A 


3.26 






5.61 


6.46 6.52 




3.24 


3.25 


6-A 8.67 




Average 6.78 


19-A 


3.10 




8.71 


8.69 






3.13 


3.11 


Average 


6.88 




20-A 
22-A 
23-A 
24-A 
25-A 


3.90 
3.94 
3.06 
3.07 
3.48 
3.45 
2.60 
2.60 
2.68 
2.72 


3.92 
3.06 
3.46 
2.60 
2.70 








Average 


3.48 



Table 21 — Loss on Ignition 
San Joaquin Sandy Loam 



ample 


A 

% 


Average 

% 


10 


2.13 






2.17 


2.15 


11 


3.23 






3.20 


3.21 


12 


5.37 






3.22 


4.29 


13 


2.94 






2.96 


2.95 


17 


1.85 






1.88 


1.86 


18 


1.82 






1.83 


1.82 


21 


1.68 






1.69 


1.68 


26 


3.30 


3.30 


Avera 


ge 


2.66 



B 

% 


Average 
% 


2.32 




2.27 


2.29 


6.33 




6.16 


6.24 


2,97 




3.18 


3.07 


6.58 




6.75 


6.66 


2.54 




2.61 


2.57 


2.18 




2.18 


2.18 


1.60 




1..56 


1.58 


6.97 




6.95 


6.96 




3.94 



C 

% 


Average 

% 


3.10 




3.08 


3.09 



5.54 


5.54 


3.97 




6.07 


5.02 


Noi 


sample 


2.90 




2.89 


2.89 


3.31 




3.33 


3.32 


6.18 






6.18 




4.67 



408 University of California Pablications in Agricultural Sciences [Vol. 3 

Calcium 

The Diablo, Altamont, and Hanford soils were analyzed for their 
calcium in the A horizon only, while the A, B, and C horizons of the 
San Joaquin sandy loam were analyzed (tables 22, 23, and figs. 15-18). 

Diablo clay adobe. — There is much divergence in the amounts of 
CaO in this type, varying from 0.36% to 2.05%, with the average 
of 1.23%. 

Altamont clay loam. — In this type there is a little greater varia- 
tion than in the Diablo samples, with a range of from 0.78% to 5.64%, 
averaging 2.44% CaO. In both this soil and in the Diablo the wide 
variation in the lime content is undoubtedly due to the nature of the 
parent rock, since the soils are residual. 

San Joaquin sandy loam. — In the CaO content there is no uni- 
formity among the samples. The A samples of this type contain from 
0.47% to 2.98%, with an average of l.%f>%. It would seem that tlie 
materials from which the soils were derived were of varying composi- 
tion. For from the present climatic conditions soil no. 25 is the one 
subject to the least leaching, and yet has the least CaO content. The 
B and C percentages follow the surface very closely — sufficiently so 
to necessitate no particular explanation. The range of variation in 
the B horizon is from 0.11% to 2.42%, and the average is 1.427o. 
The C samples vary from 0.17% to 2.81%, with the average of 1.52%. 

Hanford fine sandy loam. — The A samples of this type contain 
from 2.56% CaO to 4.69%, with 3.33% as the average. The varia- 
tions are not so marked among the series of this type as in the cases 
of the other three soils. The absolute range is nearly as great, but 
the relative variation is less. 

Even though there are differences between the average CaO con- 
tent in the several types, the wide variation in the amount found in 
the several samples of a given type, and the overlapping of these 
amounts from the different types entirely preclude any statement 
tliat as regards the calcium content the soils of any one type are 
elosel.y similar to one another, or that one type has a higher or lower 
lime content than another. 



1919] Pendleton: A Study of Soil Types 

Table 22 — Calcium as CaO 
(Surface horizons only) 



Di8 


iblo Clay Adobe 


Altamont Clay 


Loam 


Hanford Fine 
Loam 


Sandy 


' 


' 


% 


% 


% 


% 


1-A 


1.S6 




3-A 


5.64 




14-A 2.91 






1.80 


1.83 






5.64 


2.99 


2.95 


2-A 


2.12 




4-A 


0.92 




1.5-A 2.98 






1.98 


2.0.5 




0.88 


0.90 


3.22 


3.10 


5-A 


0..56 




7-A 


0.89 




16-A 2.48 






0.17 


0,36 




0.67 


0.78 


2.65 


2.56 


6-A 


0.67 


0.67 


A 


verage 


2.44 


19-A 3.28 
3.17 


3.22 


Average 


1.23 








20-A 2.69 
















2.73 


2.71 














22-A 3.80 
















3.92 


3.86 














23-A 2.88 
















3.00 


2.94 














24-A 3.88 
















4.00 


3.94 














2.5-A 4.58 
















4.80 


4.69 














Average 


3.33 



Table 23 — Calcium as CaO 
iSan Joaquin Sandy Loam 



Sample 


A 


Average 


B 


Average 

% 


C 

% 


Average 

% 


10 


0.67 




0.S2 




1.11 






0.62 


0.64 


1.03 


0.92 


1.12 


1.11 


11 


1.94 




1.62 




1.65 






1.26 


1.60 


1.70 


1.66 


1.55 


1.60 


12 


3.12 




2.21 




2.61 






3.50 


3.31 




2.21 


3.01 


2.81 


13 


2.S3 




2.38 




2.46 






3.13 


2.98 


2.46 


2.42 


2.79 


2.62 


17 


1.83 




1.92 




No sample 




2.08 


1.95 


2.08 


2.00 






18 


1.40 




1.00 




1.48 






1.34 


1.37 


1.45 


1.22 


1.42 


1.45 


21 


0.91 




0.89 




0.85 






. 0.84 


0.87 


0.83 


0.86 


0.89 


0.87 


26 


0.48 




0.13 




0.17 






0.47 


0.47 


0.10 


0.11 


0.17 


0.17 


Averaj 


"e 


1.65 




1.42 




1.52 



410 University of California PuWications in Agricultural Sciences [Vol. 3 

Magnesium as MgO 

Diablo clay adobe. — This type shows a moderate variability in the 
magnesium content, with from 1.137o MgO to 3.26%, averaging 
2.09%. The largest quantity is three times that of the smallest 
(tables 24, 25, figs. 15-18). 

Altamont clay loam. — Within the three samples of this type the 
range in the MgO content is very great, from 0.07% to 1.90%, with 
the average of 1.05%. The largest is twenty-seven times that of the 
smallest. 

San Joaquin sandy loam. — The total MgO in the samples of the 
type is low, considering that some soils reported by Hilgard contain 
from 1% to 3% magnesia by the acid digestion. The variation within 
the A horizon is from 0.3-1% to 0.90%, with the average of 0.62%, i.e., 
the largest is three times the smallest. The quantities in the B horizon 
are somewhat erratic as compared with those of the surface, yet in 
both the B and C horizons the results approach those of the surface 
sufficiently to give a rough parallelism. The greater amount of clay 
and fine silts with the increase of depth gives, as one would expect, 
an increase of magnesium. The average MgO content in the B horizon 
is 0.81%, and in the C horizon 1.05%. 



Table 24 — Magnesium as MgO 
(Surface horizon only) 



Diablo Clay Adobe 


Altamont Clay 


Loam 


Hanford Fine 
Loam 


Sandy 


% 


% 


r/^ 


% ' 


% 


% 


1-A 1.64 




3- A 1.S5 




14-A 2.49 




2.20 


1.92 


1.95 


1.90 


2.49 


2.49 


2-A 2.16 
1.95 


2.05 


4-A 1.21 
1.17 


1.19 


1.5-A 0.93 
1.02 


0.97 


5-A 1.23 
1.03 


1.13 


7-A 0.09 
0.05 


0.07 


16-A 1.10 
0.99 


1.04 


6-A 3.62 

2.90 

Average 


3.26 
2.09 


Average 


1.05 


19-A 2.11 

1.99 
20-A 1.77 

1.92 
22-A 2.44 

2.71 
2.3-A 1.94 

1.70 
24-A 2.14 

2.13 
25-A 2.31 

2.40 
Average 


2.05 

1.84 

2.57 

1.82 

2.13 

2.35 
1.92 



19U)] Pendleton: A Sttidy of Soil Types 411 

Hanford fine sandy loam. — The MgO content of the surface soil 
varies from 0.97% to 2.57%, averaging 1.92%. The relative varia- 
tion within this type is about that of the Diablo and San Joaquin 
types. 

Comparing the average amounts of magnesium oxide in the sur- 
face horizon of the several types, we find the San Joaquin with 0.56%, 
the Altamont with 1.05%, the Hanford with 1.93%, and the Diablo 
with 2.09%. The averages do not signify much, however, because of 
the wide ranges within the types. Therefore as regards magnesium 
the types are neither distinct nor are the soils within the type 
closely similar. 

Table 2.5 — Magnesium as MgO 
San Joaquin Sandy Loam 



Sample 


A 


Average 


B 


Average 

% 


C 


Average 

% 


in-A 


0.31 




0.33 




0.53 






0.30 


0.30 


0.45 


0.39 


0.53 


0.53 


ll-A 


0.79 




1.21 




1.48 






0.44 


0.61 


1.22 


1.21 


1.25 


1.36 


12-A 


0.83 




0.79 




1.57 






0.79 


0.81 




0.79 


1.62 


1.59 


13- A 


0.90 




1.70 




1.67 






0.80 


0.8.5 


1.63 


1.66 


1.82 


1.74 


17-A 


0..53 




0..51 




No sample 




0.74 


0.63 


0.77 


0.64 






18-A 


0..50 




0.40 




0.64 






0.48 


0.49 


0.69 


0..54 


0.75 


0.69 


21-A 


0.29 




0.28 




0.52 








0.29 


0.31 


0.29 


0.56 


0.54 


26-A 


0..50 




0..52 




0.52 






0..52 


0..51 


0.44 


0.48 


0.53 


0.52 


Average 


0..56 




0.7.5 




1.00 



Phosphorus as P^Os 

Diablo clay adobe. — The variations in the PjOj content in the 
samples of this type are relatively small, from 0.092% to 0.162%, 
with 0.108% as the average (tables 26, 27, figs. 11-14). 

Altamont clay loam. — The range of variation in the amount of 
PjOg is large, from 0.031% to 0.265%, the largest quantity being eight 
times the smallest. The average is 0.132%. 



412 University of California Publications in Agricultural Sciences [Vol. 3 

San Joaquin sandy loam. — The variations in the PnO,-, content of 
the surface soil are from 0.039% to 0.11%, with the average 0.068%. 
The curve is fairly regular. The subsoils follow the surface in a gen- 
eral way. The B horizon samples vary in the phosphoric acid con- 
tent between 0.028% and 0.156%, and average 0.069%,. The C sam- 
ples vary between 0.03% and 0.109%, and average 0.067%. The 
averages of the three horizons are seen to be almost identical. No 
particular significance can be attached to the minor variations. 

Hanford fine sandy loam. — The P2O5 content in the samples of 
this type is very variable, from 0.195% to 0.819%), with the average 
of 0.363%. The average of the San Joaquin sandy loam samples is 
0.069%, of the Diablo clay adobe 0.108%, of the Altamont clay loam 
0.132%, and of the Hanford fine sandy loam 0.363%. Except between 
the Diablo and Altamont types these averages would show considerable 
differences, if it were not that the samples freqviently show such wide 
departures from the averages. The ranges of the several types fre- 
quently overlap. 









Table 26 — Phosphorus as P^O, 
















(Surface horizon 


only) 












Diablo Clay Adobe 


Alta 


Hail 
mont Clay Loam 


ifoi 


r<l Fine Si 
Loam 


indy 






% 


% " 




% 


% 




% 


% 


1- 


-A 


0.088 




3-A 


0.278 


14-A 




0.373 








O.OflS 


0.092 




0.2.52 


0.265 




0.292 


0.333 


2- 


-A 


0.064 




4-A 


0.081 


1.5- A 




0.287 








0.078 


0.071 




0.117 


0.099 




0.260 


0.273 


5- 


-A 


0.137 




7-A 


0.0.S4 


IR-A 




0.260 








0.082 


0.10!) 




0.028 


0.031 




0.277 


0.268 


6- 


-A 


0.143 

O.lSl 
Average 


0.162 
0.108 


A- 


rerage 


0.132 19-A 
20-A 
22-A 
23-A 
24-A 
2.J-A 




0.303 
0.272 
0.190 
0.200 
0.397 
0.401 
0.242 
0.270 
0.421 
0.4.54 
O.S79 
0.759 


0.287 
0.195 
0.,399 
0.256 
0.437 
0.S19 














Average 


0.363 



Pendleton: A Study of Soil Types 

Table 27 — Phosphorus as PjOj 
San Joaquin Sandy Loam 



Sample 


A 

% 


Average 


B 


Average 
% 


C 


Average 

% 


10 


0.118 




0.060 




0.047 






0.102 


0.110 


0.068 


0.064 


0.057 


0.052 


11 


0.049 




0.047 




0.049 






0.060 


0.054 


0.046 


0.046 


0.028 


0.028 


12 


0.0.1- 




0.028 




0.064 






0.071 


0.064 




0.028 


0.095 


0.078 


13 


0.049 




0.037 




0.036 






0.064 


0.056 


0.038 


0.039 


0.024 


0.030 


17 


0.036 




0.041 




No sample 




0.042 


0.039 


0.082 


0.061 






18 


0.04.S 




0.097 




0.086 






0.0.5.5 


0.049 


0.074 


0.085 




0.086 


21 


0.069 




0.088 




0.094 






0.068 


0.068 


0.066 


0.077 


0.062 


0.078 


26 


0.117 




0.130 




0.120 






0.092 


0.104 


0.182 


0.156 


0.098 


0.109 


Averaj 


ae 


0.068 




0.069 




0.067 



Potassium as KoO 

Diablo clay adobe. — There is a moderate range in the variation in 
the amount of K^O within this type, the lowest amount being 1.48% 
and the highesst 2.06%, the four samples averaging 1.71% (table 28, 
figs. 15-18). 

Altamont clay loam. — A greater variation, from 1.09% to 2.14%, 
of K„0, occurs in the three samples of this type. The average is 
1.74%. 

San Joaquin mndy loam. — This type shows the greatest variation, 
from 0.98% to 2.84%. But even so, the the largest quantity of K,0 
is less than three times the smallest. 1.88% K„0 is the average of 
the eight samples. Nos. 11 and 12 of this type show the smallest 
amounts of K.O of anj' of the twenty-four samples. 

Hanford fine sandy loam. — The variation in the KoO content of 
the samples of this type is not great — from 1.73% to 3.16%, with 
the average of 2.33%. This is the highest average, as the Diablo clay 
adobe samples show 1.71%, the Altamont clay loam 1.74%, and the 
San Joaquin sandy loam 1.88%. Because of the considerable range 
in the amounts of K„0 for the several samples of a type, and because 
of the many overlappings of the values for one type over another, 
the averages do not mean much and do not show the soils within a 
type to be closely similar, nor do they show the types distinct. 



University of California Publications in Agricultural Sciences [Vol. 3 

Table 28 — Potassium as K.O 

(J. Lawrence Smith Method) 

Hanford Fine Sandy 



Di 


ablo Clay 


Adobe 


Altamo 


nt Clay Loam 


San Joaqt 


Lin San. 


dy Loam 




Loam 




No. 


% 


Average 
% 


No. 


% 


Average 
% 


No. 


Cf^ 


Average 


No. 


Average 
% % 


1-A 


1.68 




3-A 


1.06 




14-A 


1.79 




10-A 


2.14 






1.67 


1.67 




1.13 


1.09 




1.67 


1.73 




3.12 


2.13 


2-A 


1.62 




4-A 


1.92 




1.5- A 


2.54 




11-A 


0.99 






1.69 


1.65 




2.36 


2.14 




2.62 


2.58 




0.98 


0.98 


.5-A 


1.45 




7-A 


1.90 




16-A 


2.42 




12-A 


1.03 






1.51 


1.48 




2.10 


2.00 




2.46 


2.44 




1.02 


1.02 


6-A 


2.01 
2.12 


2.06 


A- 


veiage 


1.74 


19-A 


2.10 
2.03 


2.06 


13-A 


1.50 


1.50 


Average 


1.71 








20-A 


2.00 




17-A 


2.40 


















1.81 


1.90 




2.24 


2.32 














22-A 


2.68 
2.62 


2.65 


18-A 


2.07 
2.28 


2.17 














23-A 


3.10 
3.23 


3.16 


21-A 


2.81 
2.88 


2.84 














24-A 


2.29 

2.21 


2.25 


26-A 


2.04 
2.09 


2.06 














25-A 


2.18 
2.21 


2.19 


A 


Lverage 


1.88 














A- 


s'erage 


2.33 









BACTERIOLOGIC.Vrj DaTA 

The bacteriological work was not entirely satisfactory, jiartly be- 
canse the conditions in one of the incubators were not all that might 
be desired, and partly because of the refractory physical properties 
of some of the soils. The Diablo and Altamout types, in all three 
horizons, were very heavy and hard to mix and keep in even fair 
physical condition. The San Joaquin soils were predominantly of a 
heavy texture in the B and C horizons, while the surface horizon 
was light and the crumb structure was entirely lost if even a siihriU 
excess of water was added to the culture. 



A M MONIFIC ATION 

There are very marked differences between the various types in 
this determination, though the samples in a given type vary among 
themselves to a large extent. 

Diablo clay adobe. — The highest ammonia production was about 
three times the lowest, 7.7 mg. and 26 mg. In both this type and 
the following, the B and C horizons follow the surface horizon quite 



1919] 



Pendleton : A Study of Soil Tyves 



40 



30 



S 20 



^ 






^\ 






-\o 


A 


^ 


"N 









5. 



Soi Is 



Fig. 19-A, 



Fig. 19a. Graph sliowing ammonificatioii in the four samples of Diablo clay 
adobe. The quantities are expressed iu terms of nitrogen produced per 100 
grams of soil with 2% of dried blood. 



\ 






N 


A 


\ 




?/^^ 


s \ 
\ \ 


^^-^"^ 


~'JZ 





75 



5Q 



as 



Soils 
Fiq. IS-B 

Fig. 19b. Graph showing nitrogen fixation in the three horizons of the four 
samples of Diablo clay adobe. The quantities are expressed in terms of milli- 
grams of nitrogen fixed per gram of mannite in 50 grams of soil. 



416 University of California Publications in Agricultural Sciences [Vol. 3 

closely from sample to sample (table 28 and fig. 19a). This maj' be 
due to the textures, which are quite similar throughout the soil column. 
The averages for the three horizons were : A, 18.6 mg. ; B, 12.6 mg. ; 
and C, 8.9 mg. 



^^ A 

^^ B 

^^^^ ^ 



3 4 7 Soils 

Mg N. as NH3 Produced 
Fig. 20a. Graph showing ammonification in the three horizons of the three 
samples of Altamout clay loam. 



\ 








\ 

\ 
\ 


\ 






\ 

X 


\ 

\ 


\ 


\ 









\ 



3 4 7 Soils 

Mg N. Fixed 
Fig. 20b. Graph showing nitrogen fixation in milligrams in the three horizons 
of the three samples of Altamont clay loam. 



Altamont clay loam. — As regards horizon A the amovmt of am- 
monia produced in one soil is three times that in the lowest, 10 mg. 
nitrogen and 33 mg. nitrogen as ammonia, with 8.9 mg. as the average 
(table 30 and fig. 20a). The amount of nitrogen as ammonia pro- 
duced in the B horizon averaged 12.6 mg., in the C horizon 8.9 mg. 



1919] 



Pendleton: A Study of Soil Types 



San Joaquin sandy loam. — The amount of ammonia produced in 
the A horizon varied between 30.4 mg. of nitrogen and 57.1 mg., the 
average was 40.2 mg. (table 31 and fig. 21a). The production of 
ammonia, in milligrams of nitrogen, by the B samples varied between 
4.5 mg. and 38.1 mg., -with 20 mg. as the average. In the C samples 
the variation was nearly as great, between 5.7 mg. and 32 mg., with 
the average of 20.9 mg. Thus there are notable variations among the 




10 II 1-' 13 17 IS 21 26 Soils 

Mg N. as NHa produced 
Fig. 2lA. Graph showing ammonification in tlie three horizons of the eight 
samples of San Joaquin sandy loam. 



samples of this type, the proportional variation being very great, con- 
sidering the three horizons. Possibly the reason that the B and C 
horizons are so divergent from the surface is that there is a very 
marked variation in the texture between the surface horizon and 
those below the surface. 

Hanford fine sandy loam. — The variation is large here also (table 
32, fig. 22a), the largest quantity of ammonia produced in the surface 
soil is twice that of the smallest production, 72 mg. and 35 mg. The 
subsoil variations, in a general way, parallel those of the surface. 
The average production of ammonia in the three horizons is as fol- 



418 University of California Publications in Agricultural Sciences [Vol. 3 

lows : A, 56.9 mg. nitrogen ; B, 46.3 mg. nitrogen ; and C, 38.7 nig. 
nitrogen. In attempting to correlate the variations in ammonifying 
powers with the known variations of the soils, or with the known his- 
tories of the soils, there seem to be no relations of significance. 

The Altamont and Diablo types are about alike in their low am- 
monifying power. The Hanford and San Joaquin are both higher 
and nearer to each other than to the two heavy types, yet the Hanford 
is noticeably higher than the San Joaquin. This is as one would ex- 
pect, from a knowledge of the soils in the field. Considering the types 
as a whole, as represented by the A horizon, there are more marked 
variations between the types than between the samples of a given type 
though the variations within a given type are very large. 



Table 29 — Ammonific.\tion 

Diahlo Clay Adobe 
Milligrams N as NH:, Produced 
B 



Sample 


Cultures 


Cheeks 
average 


Increase 
checks 


Cultures 


Checks 
average 


Increase 
checks 


Cultures 


Checks over 
average checks 


1 


31.48 






28.58 






24.24 






40.32 


2..52 


33.38 


22.98 


2.28 


23.50 


14.99 


2.42 17.19 


2 


19.81 






9.45 






8.41 






17.07 


1.68 


16.76 


9.84 


1.91 


7.73 


9.95 


1.05 8.13 


5 


15.90 






11.55 






No sample 






1.75 


14.15 


12.54 


1.54 


10.50 






6 


12.33 






7.76 






12.33 




Averag 


;e 


2.11 


10.22 
18.63 


13.55 


2.07 


8.58 
12.58 


12.33 


2.03 10.30 
11.87 



Table 30 — Ammonification 

Altamont Clay Loam 
Milligrams N as NH3 Produced 



Sample 


Cultures 


Checks 
average 


Increase 
over 
checks 


Cultures 


Checks 
average 


checks 


Cultures 


Checks 
average 


Increase 
checks 


3 


8.14 






6.97 






5.89 








10.58 


1.68 


7.68 


7.15 


1.40 


5.16 


4.91 


1.54 


3.86 


4 


19.75 






6..59 






5.41 








19.12 


2.66 


16.77 


6.67 


1.36 


5.27 


5.12 


1.19 


4.07 


7 


28.66 






19.66 






8.00 








27.53 


2.03 


26.06 


16.25 


1.75 


16.20 


12.37 


1.33 


8.95 


Average 




16.84 






8.88 






5.63 



1919] 



Pevdleton: A Study of Soil Types 



Table 31 — Ammonification 
San Joaquin Sandy Loam 
Milligrams N as NH3 Produced 
B 



Sample 
10 


Cultures 
54.24 


Checks 
average 


over 
checks 


Cultures 
42.63 


Checks 
average 


Increase 
checks 


Cultures 
28.89 


I 

Checks 


checks 




41.95 


1.72 


46.73 


36.11 


1.28 


38.09 


38.25 


1..59 


31.98 


11 


44.47 






7.47 






6.05 








73.23 


1.70 


57.15 


12.52 


1.81 


8.18 


6.78 


1.68 


4.78 


12 


44.48 






18.73 






10.91 








40.07 


1.56 


40.71 


21.81 


1.50 


18.77 


6.11 


1.14 


7.87 


13 


41.66 






5.41 






3.80 








45.94 


1.30 


42.50 


5.36 


0.86 


4.52 


15.17 


0.88 


8.60 


17 


30.19 






27.59 






Nc 


sample 






.33.88 


1.66 


30.37 


20.68 


1.51 


22.62 








18 


.35.04 






30.56 






21.96 








35.24 


1.48 


33.66 


22.81 


1.30 


25.38 


16.92 


1.47 


1.7.97 


21 


34.44 






37.41 






2.5.72 








30.89 


1.48 


31.18 


37.74 


1.38 


36.19 


29.66 


1.42 


26.27 


26 


40.81 






7.50 






9.08 










1.64 


39.17 


8.41 


1.44 


6.51 


5.43 


1..54 


5.71 


Averag 


e 




40.18 






20.03 






12.89 



Table 32 — Ammonipication 
Eanford Fine Sandy Loam 
Milligrams N as NH3 Produced 
B 



Sample 


Cultures 


Checks 
average 


checks 


Cultures 


Checks 
overage 
Horizons 


Increase 
checks 


Cultures 


Checks 
average 


over 
checks 


14 


37..35 






27.96 






14.39 








43.57 


1.78 


38.68 


48.46 


1.46 


36.75 


41.70 


1.24 


26.80 


15 


33.11 






45.68 






.59.90 








41.75 


1.75 


35.68 


48.38 


1.70 


45.33 


52..59 


1.62 


54.62 


16 


56.59 






44.08 






44.58 








56.77 


1.83 


54.85 


42.10 


1.61 


41.48 


52.10 


1.69 


46.65 


19 


52.92 






46.70 






24.56 








51.85 


1.47 


50.91 


38.92 


1.13 


41.68 


28.12 


1.24 


25.10 


20 


72.49 






45.49 






22.05 








.74.21 


1.36 


71.99 


38.52 


1.03 


40.97 


30.35 


1.00 


25.20 


22 


64.92 






57.44 






46.08 








67.56 


1.75 


64.49 


55.34 


1.51 


54.88 


47.55 


1.60 


45.21 


23 


71.56 






50.84 






35.15 








68.66 


1.61 


68.50 


43.01 


1.37 


45.55 


.3.5.23 


1.35 


33.84 


24 


65.02 






50.09 






37.56 








59.51 


1.50 


60.76 


46.54 


1.32 


46.99 


40.21 


1.33 


37.55 


25 


68.20 






69.29 






61.01 








67.29 


1.43 


66.31 


60.03 


1.25 


63.41 


47.70 


1.22 


53.13 


Average 




56.91 






46.34 






38.67 



420 University of California Publicatiotts in Agricultural Sciences [Vol.3 

Nitrogen Fixation's 

D'mhlo cl<iy adobe. — This type shows the highest quantity of nitro- 
gen fixed, 9.6 mg., with the subsoil quantities, much lower than the 
surface. The variation within the type is seen to be the largest of that 
in any of the types. 

Altamont clay loam. — The surface samples have 1.0, 4.7, and 9.1 
mg. nitrogen (table 34 and fig. 20b). The soils shows a wide diver- 
gence between the surface samples and between the surface and sub- 
soils. This is to be expected in the heavier soils. 



\ 














\ 

\ 

•v \ 














\ 


N \ 
\ 










^^ 



Mg N. Fixed 

Fig. 2lB. Graph showing nitrogen fixation in the three horizons of the 
eight samples of San Joaquin sandj' loam. 



San Joaquin sandy loam. — The quantity fixed in the A horizon 
(table 35 and fig. 21b) is small and quite variable. It is between 
nothing and 5.5 mg., with the average of 1.9 mg. Instead of nitrogen 
fixation denitrifieation took place in a number of cases, especially in 
horizon C. Considering the wide variation in textures of the horizons, 
it is rather odd that there should not be a greater variation between 
the soils from the various depths. 

Hanford fine sandy loam. — The amount of nitrogen fi:xed by the 
surface soil (table 36, and fig. 22b) averages much higher, 5.7 mg., 
than that in the San Joaquin sandy loam, though the range of varia- 
tion is about the same. It is noticeable that the amounts of nitrogen 
fixed by the B and C horizons of the soils nos. 14 and 19 are much 



28 All of the figures on nitrogen fixation refer to the milligrams of nitrogen 
fixed per gram of mannite in 50 grams of soil (table 33 and figs. 9-13). 



1919] 



Pendleton: A Study of Soil Types 



less (even to denitrifieation ) absoliitdy and relativelj' as compared 
with the surface horizons, than the amovint fixed by the B and C 
horizons of the soils nos. 20 to 25 inclusive. 

Comparing the nitrogen fixation of the various types, there seem 
to be no characteristic differences between the heavy Altamont and 
Diablo types, while the lighter Hanford and San Joaquin types are 
considerably different from each other. As a whole there is but a fair 
degree of similarity between the samples of a given type. The degree 
of variation within tj'pes is large. 



T.\BLE 33 — Nitrogen Fixation 

Diablo Clay Adobe 
Millierams N per gram of niannite 



aple 


Cultures 


Checks 
average 


checks 


Cultures 


Cheeks 
average 


checks 


Cultures 


Increase 
Checks over 
1 average checks 


1 


60.2.5 






31.52 






22.77 






63.40 


52.22 


9.60 


29.56 


34.67 


-4.13 


24.87 


28.61 -4.79 


2 


55.34 






32.92 






30.47 






49.39 


45.88 


6.48 


38.18 


33.80 


1.75 


32.22 


29.77 1.57 


5 


48.68 






35.73 








No sample 




48.68 


41.92 


6.76 


37.12 


32.39 


4.03 






6 


45.88 






39.64 






35.02 






46.86 


58.49 


-12.12 


42.72 


50.77 


-9.59 


39.01 


39.05 -2.03 


Average 




4.71 






1.44 




0.52 



Table 34 — Nitrogen Fixation 

Altamont Clay Loam 

Milligrams N fixed per gram of mannite 



Sample 


Cultures 


Checks 
average 


checks 


Cultures 


Checks 
average 


Increase 
checks 


Cultures 


Checks 
average 


checks 


3 


71.26 






49.04 






37.13 








70.40 


61.71 


9.12 


51.84 


43.78 


6.66 


38.51 


33.76 


4.06 


4 


60.25 






28.02 






20.31 








52.19 


51.49 


4.73 


27.32 


26.48 


1.19 


21.01 


20.48 


0.18 


7 


52.95 






37.75 






30.81 








53.44 


52.12 


1.08 


37.40 


36.60 


1.00 


27.18 


29.94 


-0.94 


Average 




4.98 






2.95 






1.41 



422 University of Cuiiforina PuhJicatioiis in Agricultural Sciences [Vol.3 

% 



























\ 


^ 


\ 


^/ 
















/ 


/ 


N / 


^ 




/ 






/ , 

/ / 


/ 

/ 




\ 
\ 




/ 

/ , 

/ / 


\ 

\ 
\ 
\ 


— -^ 


/ / 

/ 
/ 

/ 


1 
1 

1 


^ 


\ 
\ 

\ 
\ 
\ 




1 

1 

1 
1 
1 


\ 

\ 

\ 
> 


^^.. 


t 


1 




\ 

V 

> 




1 
1 
1 









































1-4 15 16 19 JO 22 23 24 26 Soils 

Mg N. as NHs produced 
Fig. 22a. Grajih showing ammonifieation in the three horizons of the nine 
samples of Hanford fine sandy loam. 




H I.-) 



23 24 



IG 10 20 22 

Mg N. Fixed 

Fig. 22b. Graph showing nitrogen fi.\atiou in the three horizons of the nine 
samples of Hanford fine sandy loam. 



1919] 



Pendleton: A Study of Soil Types 



Table 35 — Nitrogen Fixation 

San Joaquin Satidy Loam 

Milligrams N fixed per gram of mannil 



Sample 


Cultures 


Checks 
average 


Increase 
checks 


Cultures 


Checks 
average 


^ 
checks 


Cultures 


Checks 


Increas( 
checks 


10 


25.01 






17.16 






15.83 








23.47 


18.73 


5.51 


16.67 


13. .59 


3.32 


18.14 


10.33 


6.65 


11 


27.25 






22.91 






21.72 








31.87 


2.5.15 


4.41 


22.84 


21.78 


1.09 


22.00 


19.43 


2.43 


12 


25.85 






20.17 






18.98 








23.82 


23.26 


1.57 


17.09 


16.56 


2.07 


20.10 


20.41 


-0.87 


13 


22.77 






18.49 






13.31 








21.58 


20.00 


2.17 


17.86 


20.21 


-2.04 


14.50 


16.35 


-2.45 


17 


1.3.52 






9.46 








No samjile 




13.45 






10.23 












18 


15.55 






8.76 






9.18 








13.24 


13.73 


0.66 


8.20 


S.09 


0.39 


11.42 


9.74 


0.56 


21 


14.85 






7.98 






6.58 








16.11 


14.50 


0.98 


6.44 


5.96 


1.25 


7.28 


7.01 


-0.07 


26 


19..54 






12.61 






7.14 








19.34 


20.34 


-0.94 


12.82 


13.34 


-0.72 


7.36 


8.24 


-0.99 


Average 




1.91 






1.09 






1.20 



Table 36 — Nitrogen Fixation 
Hanford Fine Sandy Loam 

Milligrams N fixed per gram of maiinit 
B 



Sample 


Cultures 


Checks 
average 


checks 


Cultures 


Checks 
average 


Increase 
checks 


Cultures 


Checks 


checks 


14 


71.52 






41.61 






31.10 








63.05 


59.61 


7.67 


41.69 


41.01 


0.64 


30.19 


29.07 


1.57 


15 


38.18 






22.07 






12.40 








29.56 


26..55 


7.32 


21.09 


20.12 


1.46 


14.08 


13.87 


-0.63 


16 


30.33 






16.46 






9.67 








32.92 


27.84 


3.78 


16.04 


14.85 


1.40 


8.97 


10.61 


-1.29 


19 


2.5.56 






14.43 






11.77 








26.41 


22.49 


4.49 


13. .59 


12.29 


1.72 


12.33 


11.80 


-0.25 


20 


38.04 






22.84 






17.09 








38.11 


29.66 


8.41 


23.61 


16.39 


6.83 


20.60 


11.52 


7.32 


22 


3.5.59 






22.20 






17.30 








31.80 


29.17 


4.52 


23.40 


17.23 


5.57 


16.46 


11.87 


5.01 


23 


38.95 






19.19 






11.90 








43.57 


36.10 


5.16 


20.25 


14.57 


.5.15 


11.98 


8.90 


3.04 


24 


28.79 






19.89 






18.52 








34.61 


25.67 


6.03 


21.52 


16.95 


3.75 


17.51 


13.91 


4.11 


25 


26.55 






17.86 






15.55 








26.41 


22.70 


3.78 


17.93 


15.51 


2.38 


13.87 


11.31 


3.41 


Average 




5.69 






3.21 






2.27 



424 University of California Publications in Agricultural Sciences [Vol. 3 

NlTRIFICATION^O 

The most noticeable thing about the nitrification results is the 
very wide range of variation in the various representatives of the 
Hanford fine sandy loam as compared with the quite uniform and 
consistent results obtained with the other types. 

Diablo cl-ay adobe. — The percentage of nitrogen nitrified (table 
37, 38, and fig. 23) is uniformly low. The B samples showed a less 
vigorous nitrifjdng flora (except in the case of no. 6) than the sur- 
face ones. Dried blood in the quantities used seems to depress the 



A. S.N.-I- Cottonseed Meal 
A S. N.-|-(NH<)2S0i 



A S. N. + Dried Blood 
A Soil Nitrogen 



Percentages of N. Nitrified 
Fig. 23. Graph showing the percentages of nitrogen in various nitrogen 
containing materials nitrified in the four samples of the Diablo clay adobe. 



normal activity (A horizon average 0.81%), while the (NH4)„S04 
(A horizon average 3.03%) and the cottonseed meal (A horizon 
average 2.91%), as compared with the incubated control tend to in- 
crease the percentage of nitrogen nitrified. It should be kept in mind 
that an absolute increase in the nitrogen content may accompany a 
decrease in the percentage, due to the greatly increased amount of 
nitrogen present after the addition of a nitrogenous substance. The 
variation of the samples within this type is very moderate as compared 
with the San Joaquin and Hanford tj-pes. 




29 The figures used in the discussion shows the percentages of the nitrogen in 
the cultures which were nitrified. There are two tables for the samples of each 
type. The percentages of nitrogen nitrified are rearranged in a second table for 
greater ease in comparing results. 



1919] 



Pendleton: A Siudy of Soil Types 



Altamont clay loam. — The percentages of nitrogen nitrified (tables 
39 and 40, fig. 24) are as a whole lower than in the Diablo soils. A 
similar relative effect of the sevei-al nitrogenous materials is seen, for 
(NHJ2SO4 is first, cottonseed meal, second, the soil's o-#n nitrogen 
third, and dried blood fourth in the percentages of nitrates produced. 
As in the Diablo soils the variation is not great from soil to soil. 

San Joaqum sandy loam. — A wide range of variation (tables 41, 
42, and fig. 25), from 1.2% to 4.5%, is found in the incubated control, 
possibly due, in part, to the considerable variations in the physical 
nature of the samples. The relative action of the nitrogenous ma- 



----^^ 


\ 


^ 


^\N. 


^^^ 


~^-:^ 



lA S. N.+ (NH)):SO, 
A S. N. -(-Cottonseed Meal 
A Soil Nitrogen 
A S. N.+ Dried Blood 
• Soils 



Percentages of N. Nitrified 



Fig. 24. Graph showing the percentages of nitrogen in various nitroLten 
containing materials nitrified in the three samples of the Altamont clay loam. 



terials in the soils of the San Joaquin samples as compared with tliat 
in the Diablo and Altamont soils is well shown by the following aver- 
ages of the A horizon: dried blood had 0.02%. cottonseed meal had 
0.33%, and ammonium sulfate had 0.56% of the nitrogen nitrified, 
while the incubated control had 2.47% nitrified. The soils are normally 
low in nitrogen, and this, together with the poor physical condition, 
made an unfavorable medium for any bacterial activity. This applies 
especially to horizons B and C. 

Hanford fine sandy loam. — This is by far the most inexplicable 
set of results in the nitrification studies (tables 43, 44, and fig. 26). 
The physical nature of this type is admirably suited for bacteriological 
tumbler cultures, the soil being friable, not puddling readily, and 
while in the incubator may be kept at the approximately optimum 
moisture content with little difficulty. This property is fairly con- 



426 



University of California Publications in Agricultural Sciences [Vol. 3 



stant throughout all the samples (except no. 14) and cannot well 
be supposed to affect the results greatly. No. 14 has a low nitrifying 
power throughout, but it is not representative of the type, for it is 
heavier in texture than the rest. Moreover, it had been submerged 
by river overflows shortly before the collection of the sample. One 
would expect these factors to influence the numbers and the activity 
of the bacterial flora. There is but little similarity in the way the 
different samples of the A or B horizons behave toward any given 











1 


^^ 


\ 










1 
1 




\ 
\ 


/ 

/ 








1 

1 




\ 

\ 


/ 

/ 


/ 


\^ 


y 








,y^- 


/ 


-\ 




-'^ 







Fig. 2! 
containing 
loam. 



A Soil Nitrogen 



A. .«. N.+ (NH4)2SO. 



A .S. N. +Cottonsced Meal 
12 13 17 IS 21 26 Soils 

Percentages of N. Nitrified 
Graph showing the percentages of nitrogen in various nitrogen 
iiaterials nitrified in the eight samples of the San .Joaquin sandy 



nitrogen containing material. Variations from 1% to 50%, from 
07o to 14%, from 4.57c to 8%, or from 15% to 15.5% from soil to 
soil, without regularity, give slight basis for generalizations. The 
average effect of the A horizon samples of the Hanford fine sandy 
loam as regards the several nitrogenous materials is as follows : dried 
blood, 5.62%.; cottonseed meal, 13.72%; ammonium sulfate, 3.29%; 
incabated control, 1.55%. In a general way there is a similarity 
between the effects of a given nitrogen containing material on the 
surface sample, and on the B horizon. This should be so, since these 
soils are very deep and uniform in texture. However, in the C 
horizon there were still greater deerea.ses in the bacterial activity. 



1919] Pendletoti: A Study of Soil Types 427 

As regards nitrification in general there is difficulty in showing 
any greater resemblance between the samples of a type than there is 
from type to t3'pe. In certain features, however, the types are some- 
what distinct: (1) The relation of the nitrification of the soil's own 
nitrogen to the soil's action upon added nitrogen is rather distinct 
for the types. The normal soil in the San Joaquin type gave a much 
larger per cent of nitrogen than did the soil plus the added nitrogen 
containing materials. In the Diablo tj'pe (fig. 25) the normal soil 
was about midwa.y in its production as compared with the soils to 
which the nitrogenous materials were added. In the Hanford fine 
sand}- loam the normal soils gave a much lower percentage nitrifica- 
tion than in the greater number of instances where the soils were 
treated with nitrogenous materials. (2) The relative nitrification of 
the various nitrogenous materials is somewhat distinct for the types. 
The Diablo, Altamont, and San Joaquin show the ammonium sulfate 
first, with the cottonseed meal second, and the dried blood third. The 
Hanford type shows cottonseed meal first, with dried blood second and 
ammonium sulfate third. 



Table 37 — Nitrification 
Diablo Clay Adobe 



Sample 


g;^ 


Eh'" 


a 


8 


t^'" 


t^ 


S' 


H 


Si 


S' 


tH~ 


■z 


1-A 


0.90 


104.43 


0.86 


5.35 


146.82 


3.65 


2.20 


347.22 


0.63 


5.00 


198.42 


2.50 


1-B 


0.28 


93.34 


0.30 


0.77 


135.74 


0.57 


Tr. 


336.14 




Tr. 


187.34 




1-C 


0.19 


57.22 


0.33 


0.25 


99.62 


0.25 


0.07 


300.02 


0.02 


0.16 


151.22 




2-A 


0.47 


..1.76 


0.51 


3.47 


134.16 


2.58 


4.07 


334.56 


1.22 


6.82 


185.76 


3.77 


2-B 


0.33 


67.60 


0.49 


1.17 


110.00 


1.06 


O.OS 


310.40 




0.19 


161.60 


0.12 


2-C 


0.59 


59.54 




0.29 


101.94 




0.80 


302.34 




0.80 


153.54 




5-A 


0.-17 


83.82 


0..56 


3.81 


126.22 


3.02 


1.66 


326.62 


0.51 


3.76 


177.82 


2.12 


5-B 


0.36 


64.78 


0.56 


0.42 


107.18 


0.39 


0.19 


307.58 


0.06 


0.97 


158.78 


0.61 


6-A 


0.59 


116.58 


0.51 


4.58 


158.98 


2.88 


3.13 


359.38 


0.87 


6.88 


210.58 


3.26 


6-B 


1.65 


101..54 


1.63 


3.00 


143.94 


2.08 


1.19 


344.34 


0.35 


4.55 


19.5.54 


2.32 


6-C 


0.96 


78.10 


1.23 


1.01 


120.50 


0.84 


0.37 


320.90 


0.01 


0.47 


172.10 


0.27 



428 University of California Publications in Agricultural Sciences [Vol. 3 

























\ 














t> 




\ 



















1 


















1 



















1 


















1 














u 




1 


















1 












\ 








^ 


7"^-~^ 


'■■/ 


-7--"" 


^^^x. 









-~-^ 


ZZrz^ 


/ 


/ 


'-" 




"^■^ 



A S. N.+ (NH4)!S0. 

A Soil Nitrogen 

A S. N. + Dried Bloc 



Fig. 26 
containing 
loam. 



25 Soils 
Percentages of N. Nitrified 
Graph showing the percentages of nitrogen in various nitrogen 
materials nitrified in the nine samples of the Hanford fine sandy 



Pendleton: A Study of Soil Types 





Table 


38 — Nitrification — Percentages 


OF N 


ITROCEN Nitrified 












Diablo 


Clay Adoh 


e 












Soil nitre 


Jgen 


Soil nitroge; 


nand 
ulfato 


Soil 
andd 


nitrogen 
ried blood 


Soil nitrogen 
cottonseed meal 


Sample 


A 


B 


c 


A B 


C 


A 


B 


C 


A 


B c' 


1 


0.86 


0.30 


0.33 


3.65 0.57 


0.25 


0.63 




0.02 


2.50 




2 


0.51 


0.49 




2.58 1.06 




1.22 






3.77 


0.12 


5 


0..56 


0..56 




3.02 0.39 




0.51 


0.06 




2.12 


0.61 


6 


0..51 


1.63 


1.23 


2.88 2.08 


0.84 


0.87 


0.35 


0.01 


3.26 


2.32 0.27 


Average 


0.61 


0.74 


0.52 


3.03 1.02 


0.36 


0.81 


0.10 


0.01 


2.91 


0.76 0.09 



Table 39 — Nitrification 
Altamont Clay Loam 





Soil nitrogei 


1 


Soil 


nitroKen 


and 
Ifate 


So 


il nitrogen 
dried Woo 


and 
d 


Soil nitrogen and 
cottonseed meal 




' 


C 


' 




■g 


' 




•g 


' 




g 




Sample 






1'^ 




Is 


& '^ 


gn3 


If 




■|-3 


|e 


go' 

1 = 


3-A 


0.60 


123.42 


0.49 


4.12 


165.82 


2.49 


1.17 


366.22 


0.32 


3.57 


217.42 


1.64 


3-B 


0.04 


87.56 


0.05 


0.39 


129.96 


0.32 


0.18 


330.36 




0.03 


181.56 




3-C 


0.27 


67.52 


0.40 


0.20 


109.92 


O.IS 


0.10 


310.32 




0.10 


161.52 




4-A 


1.30 


102.58 


1.27 


2.95 


144.98 


2.05 


2.34 


345.38 


0.68 


4.83 


196.58 


2.46 


4-B 


0.45 


52.96 


0.85 




95.36 




0.10 


29.5.76 






146.96 




4-C 




40.96 






83.36 






283.76 




0.20 


134.96 


0.15 


7-A 


0.50 


104.24 


0.48 


1..35 


146.64 


0.93 


0.40 


347.04 


0.12 


1.27 


198.24 


0.64 


7-B 


0.25 


73.20 


0.34 


0.32 


115.60 


0.28 




316.00 






167.20 




7-C 




59.88 






102.28 






302.68 






153.88 





Table 40 — Nitrification — Percentages of Nitrogen Nitrified 
Altamont Clay Loam 





Soil nitrogen 
ABC 


Soil 


nitrogen and 
)nium sulfate 


Soil nitrogen 
and dried blood 


Soil nitrogen and 
cottonseed meal 


/ Sample 


A 


B 


C 


A 


B C " 


ABC 


3 


0.49 0.05 


0.40 


2.49 


0.32 


0.18 


0.32 




1.64 


4 


1.27 0.85 




2.05 






0.68 




2.46 0.15 


7 


0.48 0.34 




0.93 


0.28 




0.12 




0.64 


Average 


0.75 0.41 


0.13 


1.82 


0.20 


0.06 


0.37 




1.58 0.05 



University of California Publications in Agricnltural Sciences [Vol. 3 

Table 41 — Nitrification 
San Joaquin Sandy Loam 



3:iinple 
10- A 
10-B 
10-C 

11-A 
Il-B 
11-C 

12-A 
12-B 
12-C 

13-A 
13-B 
13-C 

17-A 
17-B 

18- A 
18-B 
18-C 

21-A 
21-B 
21-C 

26-A 
26-B 
26-C 



0.52 
0.23 
0.07 

1.25 



37.46 1.4 
27.18 0.9 
20.66 0.3 



50.30 2.0 

41.56 .... 

0.14 38.86 0.4 

0.80 46.52 1.7 

0.18 33.12 0.5 

0.14 40.82 0.3 

0.49 40.00 1.2 

0.06 40.41 .... 

0.35 32.70 1.1 

0.54 28.92 1.9 
18.42 .... 

1.25 27.46 4.5 
Tr. 16.18 .... 
19.48 .... 

1.25 29.00 4.3 

11.92 .... 

0.01 14.02 .... 

0.95 40.68 2.3 
Tr. 26.28 .... 
16.48 .... 



0.24 122.26 0.2 

0.08 111.98 0.07 

0.06 105.46 0.06 

0.50 135.10 0.4 

0.02 126.36 

Tr. 123.66 



0.55 131.32 0.4 

0.11 117.92 0.09 

0.06 125.62 

0..59 124.80 0.5 

0.10 125.21 0.08 

0.25 117.50 0.2 

0.45 113.72 0.4 
103.22 



1.00 112.26 0.9 

Tr. 100.98 

0.10 104.28 1.0 

1.30 113.80 1.1 

96.72 

0.01 98.82 0.01 

0.80 125.48 0.6 

111.48 

101.28 



0.06 302.46 0.02 

292.18 

285.66 

0.27 315.30 0.09 

0.08 306.56 0.03 

Tr. 303.86 

0.09 311.52 0.03 

Tr. 298.12 

0.06 305.82 

0.07 305.00 0.02 

0.21 305.41 

0.00 297.70 



Tr. 293.92 
Tr. 283.42 



292.46 

Tr. 281.18 
284.48 

Tr. 294.00 

276.92 

0.15 279.02 

Tr. 305.68 

Tr. 291.68 

Tr. 281.48 



0.10 121.46 0.08 

111.18 

0.08 104.66 0.08 

0.95 134.30 0.7 

0.02 125.56 

Tr. 122.86 



Tr. 
Tr. 



111.46 
100.18 
103.48 



2.05 130.52 1.6 

Tr. 117.12 

0.06 124.82 



0.10 124.00 0.08 

0.69 124.41 

0.96 116.70 

112.92 

0.08 102.42 0.08 



0.13 113.00 

95.92 

0.15 98.02 

0.19 124.68 0.10 

Tr. 110.68 

100.48 



Sample 

10 

11 

12 

13 

17 

18 

21 

26 
Average 



1.4 
2.5 
1.7 
1.2 
1.9 
4.5 
4.3 
2.3 
2.47 



-Nitrification — Percentages of Nitrogen Nitrified 

San Joaquin Sandy Loam 

Soil nitrosen 
and dried blood 



0.9 0.3 

.... 0.4 

0.5 0.3 

.... 1.1 



0.2 0.07 0.06 

0.4 

0.4 0.09 

0.5 0.08 0.20 

0.4 

0.9 1.00 

1.1 0.01 

0.6 

0.56 0.03 0.18 



A B 

0.02 

0.09 0.03 

0.03 

0.02 

0.02 



Soilr 
cotti 


litrogen and 
unseed meal 


A 


B C ' 


0.08 


0.08 


0.7 




1.6 




0.08 






0.08 


0.10 




0.1 




0.33 


0.01 0.01 



1919] 



Pendleton : A Study of Soil '1 



lives 



431 



Table 43 — Nitrification 
Hanford Fine Sandy Loam 



Soil nitrogen and 



Soil nitrogen and 
dried blood 



Sample z'° 


H'" 


s 


..^ , 


F<'" 


is 


.-^ 


Eh'" 


'& 


g' 


t^"' 


g 


14-A 0.20 


119.22 




0.25 


161.62 


0.1 


10.35 


254.22 


4.1 


1.85 


166.22 


1.1 


14-B 0.45 


82.02 




0.42 


124.42 




0.23 


217.02 




0.48 


129.02 




14-C 0.07 


58.14 


0.1 


0.75 


100..54 


0.7 


0.15 


193.14 


0.1 


0.10 


105.14 


0.1 


1.5-A 1.45 


53.10 


2.7 


3.20 


95.50 


3.4 


0.40 


188.10 


0.2 


50.85 


100.10 


50.8 


15-B 0.18 


40.24 


0.4 


0.19 


82.64 


0.2 


Tr. 


175.24 




1.42 


87.24 


1.6 


1.5-C 0.03 


27.74 


0.1 


0.01 


70.14 




Tr. 


162.74 




0.03 


74.74 




16-A 0.87 


55.68 


1.6 


2.50 


98.08 


2.5 


0.50 


190.68 


0.2 


4.60 


102.68 


4.5 


16-B 0.11 


29.70 


0.4 


0.08 


72.10 


0.1 


Tr. 


164.70 




3.70 


76.70 


4.8 


16-C 0.03 


21.22 


0.1 


Tr. 


63.62 




0.05 


1.56.22 




0.17 


68.22 


0.2 


19-A 1.00 


44.98 


2.2 


2.03 


87.38 


2.3 


0.21 


179.98 


0.1 


7.48 


91.98 


8.1 


19-B 0.08 


24.58 


0.3 


0.12 


66.98 


0.2 




1.59.58 




0.20 


71.58 


0.3 


19-C 0.16 


23.60 


0.7 


0.15 


66.00 


0.2 


Tr. 


158.60 




0.20 


70.60 


0.3 


20-A 0.77 


59.32 


1.3 


1.24 


101.72 


1.2 


27.39 


194.32 


14.1 


6.19 


104.32 


5.9 


20-B 0.12 


32.78 


0.4 


0.11 


75.18 


0.1 


15.50 


167.78 


9.2 


1.45 


77.78 


1.9 


20-C 


23.04 






65.44 






158.04 




0.07 


68.04 


0.1 


22-A 0.83 


58.34 


1.4 


6.48 


100.74 


6.4 


2.68 


193.34 


1.4 


13.58 


103.34 


13.1 


22-B 0.27 


34.46 


0.8 


0.26 


76.86 


0.3 


0.04 


169.46 


0.02 


1.91 


79.46 


2.4 


22-C 0.85 


23.74 


3.6 


5.40 


66.14 


8.2 


0.52 


158.74 


0.3 


2.50 


68.74 


3.6 


23-A 1.45 


72.20 


2.0 


8.95 


114.6 


7.8 


37.25 


207.20 


17.9 


18.25 


117.20 


15.5 


23-B 0.75 


29.14 


2.6 


8.90 


71.54 


12.5 


0.47 


164.14 


0.3 


2.65 


74.14 


3.6 


23-C 0.32 


17.80 


1.8 


12.40 


60.20 


20.6 


0.02 


152.80 


0.01 


1.30 


62.80 


2.1 


24-A 0.80 


51.34 


1.6 


4.10 


93.74 


4.4 


22.35 


186.34 


11.9 


14.35 


96.34 


14.9 


24-B 0.03 


33.90 


0.1 


0.36 


76.30 


0.5 


0.46 


168.90 


0.3 


5.91 


78.90 


7.5 


24-C 0.33 


27.82 


1.1 


0.33 


70.22 


0.5 


0.63 


162.82 


0.4 


0.73 


72.82 


1.0 


25-A 0.56 


45.40 


1.2 


1.30 


87.80 


1.5 


1.30 


180.40 


0.7 


8.65 


90.40 


9.6 


2.5-B 0.32 


31.01 


1.0 


0.32 


73.41 


0.4 


Tr. 


166.01 




0.05 


76.01 


0.06 


2.5-C 0.11 


22.62 


0.5 


0.16 


65.02 


0.2 


Tr. 


157.62 




Tr. 


67.62 





Table 44 — Nitrification — Percentages of Nitrogen Nitrified 
Hanford Fine Sandy Loam 





Soi 


1 nitrogen 


Soil 


nitrogen and 
)nium sulfate 


Soil nitrogen 
and dried blood 


Soil nitrogen and 
cottonseed meal 


Sample 


A 


B C 


A 


B 


C ' 


A B 


C 


A B 


C 


^\t 




0.1 


0.1 




0.7 


4.1 


0.1 


1.1 


0.1 


2.7 


0.4 0.1 


3.4 


0.2 




0.2 




4.5 4.8 


0.2 


16 


1.6 


0.4 0.1 


2.5 


0.1 




0.2 




4.5 4.8 


0.2 


19 


2.2 


0.3 0.7 


2.3 


0.2 


0.2 


0.1 




8.1 0.3 


0.3 


20 


1.3 


0.4 


1.2 


0.1 




14.1 9.2 




5.9 1.9 


0.1 


22 


1.4 


0.8 3.6 


6.4 


0.3 


8.2 


1.4 0.02 


0.3 


13.1 2.4 


3.6 


23 


2.0 


2.6 1.8 


7.8 


12.5 


20.6 


17.9 0.3 


0.01 


15.5 3.6 


2.1 


24 


1.6 


0.1 1.1 


4.4 


0.5 


0.5 


11.9 0.3 


0.4 


14.9 7.5 


1.0 


25 


1.2 


1.0 0.5 


1.5 


0.4 


0.2 


0.7 




9.6 0.06 




Average 


1.55 


0.66 0.88 


3.29 


1..59 


3.38 


5.62 1.09 


0.09 


13.72 2.55 


0.82 



University of California Publications in Agricultural Sciences [Vol. 3 



Greenhouse Data 

There are objections to all greenhouse work due to somewhat un- 
natural conditions for the usual indicator crops, the lack of a normal 
water supply, the small amount of root space, etc. Crowding of the 
pots is also apt to cause variations. Even the slight change in the loca- 
tion of a pot on the bench will affect the growth of plants, as some of 
the elaborate precautions for moving the pots daily, and in a given 
order, testify. The outstanding advantage of greenhouse work is that 
with a given indicator crop a group of soils, or soil conditions, may be 
compared under very similar conditions. 

In the present case, the leaks in the sash allowed rain water to fall 
into some of the pots to a considerable extent. The pots so affected 
showed a poorer growth in the cases of the heavy Altamont and 
Diablo samples, where the soil was readily compacted, while in the 
poor Hanford and San Joaquin soils the pots receiving leakage water 
showed markedly better growth. 

To minimize such errors, as mucli as possible, triplicates were 
used, as above explained, besides repeating the series. In working 
out the final averages of the crop it was suggested that a selection be 
made of the crop dry weights, in case that there was a marked varia- 
tion between the triplicates, using the two weights close together, and 
excluding the third if it were widely divergent. However, when one 
begins to select certain figures from a series, and bases comparisons 
upon these alone, there is apt to be the tendency to select those figures 
that will prove tlie point in question, unless there is some known dis- 
turbing factor causing tlie divergence and which warrants the exclu- 
sion of certain figures. 

Other cases that are ratlier hard to deal with are those in which 
the number of plants reaching maturitj' was not up to the standard to 
which the series was thinned when the plants were young. This fail- 
ure may have been due to poor germination, or to accidental destruc- 
tion of the plants during growth. Sometimes less than the standard 
number of plants will give a much greater dry weight per plant than 
the normal number. It was not deemed advisable to use the weight 
per plant, but rather to use the total dry weight of the crop, and only 
consider of value the series in which the number of plants per pot 
was practically constant. 

In the greenhouse work the Diablo claj- adobe, the Altamont clay 
loam, and the Hanford fine sandy loam samples were compared by 



1919] 



Pendleton: A Study of Soil Types 



two eroppings, while one crop was grown on the San Joaquin sandy 
loam soils. The infertility of the San Joaquin soils, in some cases 
extreme, greath' retarded crop growth. 

Dkihlo clay adohe. First crop. — Due to the presence of wild oat 
seed in all the four samples of this soil, and the inability to distin- 
guish the young wild oat plants from the planted oats, wheat, or 
barley when thinning, the value of the results of the grain crops in 
this series is much decreased. The averages plotted include the total 



£5 



20 



E 



O 



10 




Soils 



Fig. 27. Graph showing the total dry matter produced by wheat, barley, 
oats, Phaseolus, bur clover, and oats and bur clover on the four samples of 
Diablo clay adobe. First crop. 



crop, whether pure or with a greater or less quantity of the wild oats, 
though the number of plants harvested was usually six or less. 
Planting the oats and bur clover together was not a success. In three 
of the soils the crop of bur clover alone was greater than that of the 
six bur clover plants plus the six oat plants. Plate 44 shows how, in 
some ca.ses, the oats dominated, and in others the bur clover was 
superior. On the soils of this tj'pe bur clover was the most satisfactory 
crop, while the white beans were the most unsatisfactory of all. 

Comparing the total crops (see fig. 27 and tables 45-50), it will 
be seen that 1, 5, 2, 6 is the order for bur clover, soil no. 1 giving the 



434 University of California Publications in Agricultiiral Sciences [Vol.3 

best crop and soil no. 6 the poorest, while nos. 5, 1, 2, 6 is the order 
for barley and wheat. Oats show nearlj^ double the crop on soil 5 
that it does on any of the other three soils. There is thus a general 
agreement between the indicators that the soils are not of the same 
productivity. 



Table 45 — Diablo Clay Adobe, First Crop 

Wheat 

Planted, November 6, 1915. Harvested, July 10, 1916 

Straw Grain Total dry matter 

r ^ ^ r ^ ^ r ^ ^ 

No. Average Average Average 

Pot plants Weight weight Weight weight Weight weight 

1-1 Wheat 2 3.65 0.25 

Oats 4 2.15 0.69 6.74 

1-2 Wheat 

Oats 6 4.05 2.47 6.51 

1-3 Wheat 1 1.83 

Oats 5 5.20 5.62 1.64 1.68 8.66 7.30 

2-1 Wheat 5 5.33 0.05 

Oats 1 0.43 5.81 

2-2 Wheat 4 3.53 0.03 

Oats 2 0.69 0.04 4.31 

2-3 Wheat 3 2.55 

Oats 3 1.39 4.63 0.49 0.21 4.43 0.84 



0.90 
0.42 
1.81 
1.02 
0.48 
0.47 



5-1 


Wheat 2 


4.33 




Oats 4 


1.56 


5-2 


Wheat 3 


7.28 




Oats 2 


3.23 


5-3 


Wheat 3 


7.09 




Oats 2 


0.64 


6-1 


Wheat 2 


2.19 




Oats 4 


1.03 


6-2 


Wheat 






Oats 5 


1.72 


6-3 


Wheat 2 


2.31 




Oats 4 


2.51 



1919] Pendleton: A Study of Soil Types 435 

Table 46 — Diablo Clay Adobe, First Crop 
Barley 
Planted, November 6, 1915. Harvested, April 28, 1916 
Straw Grain Total dry matter 



Pot 


No. 
plants 


Weight 


Average 
weight 


Weight 


Average 
weight 


Weight 


Average 
weight 


1-1 


6 


5.19 




1.06 




6.25 




1-2 


Barley 5 
Oats 1 


4.79 




0.75 




5.54 




1-3 


Barley 4 


5.75 




1.34 










Oats 2 




5.24 


0.98 


1.38 


8.07 


6.62 


2-1 


6 


5.12 




1.05 




6.17 




2-2 


6 


4.87 




1.71 




6.58 




2-3 


Barley 5 


2. 78 




0.49 










Oats 1 


0.69 


4.49 


0.23 


1.16 


4.19 


5.65 


5-1 


6 


6.59 




2.12 




8.70 




5-2 


Barley 5 






3.01 










Oats 1 


2.56 




0.25 




3.25 




5-3 


Barley 5 






3.01 










Oats 1 


8.43 


5.86 


0.04 


1.95 


11.48 


7.81 


6-1 


6 


4.62 




1.26 




5.88 




6-2 


6 


4.36 




1.25 




5.61 




6-3 


Barley 5 






0.33 










Oats 1 


3.49 


4.16 


0.24 


1.02 


4.06 


5.18 



Table 47 — Diablo Clay' Adobe, First Crop 

Oats 

Planted, November 6, 1915. Harvested, May 8, 1916 

Straw Grain Total dry matter 



Pot 


No. 
plants 


Weight 


Average 
weight 


Weight 


Average 
weight 


Weight 


Average 
weight 


1-1 


6 


4.11 




1.24 




5.35 




1-2 


6 


6.56 




2.59 




9.15 




1-3 


6 


4.76 


5.14 


1.34 


1.72 


6.10 


6.86 


2-1 


6 


4.36 




1.10 




5.46 




2-2 


6 


total only 


total only 


6.92 




2-3 


6 


6.66 


5.51 


2.06 


1.58 


8.72 


7.03 


5-1 


7 


7.55 




2.59 




10.15 




5-2 


6 


10.66 




4.38 




15.04 




5-3 


6 


10.10 




3.12 




13.22 




6-1 


6 


4.70 




1.48 




6.18 




6-2 


6 


6.81 




1.42 




8.22 




6-3 


6 


6.78 




1.09 




7.88 





One barley plant 



436 



University of Calif ornia Publications in Agricultural Sciences [Vol. 3 



Table 48 — Diablo Clay Adobe, First Crop 

Bur Clover 

Planted, November 6, 1915. Harvested, May 8, 1916 

Straw Grain Total dry matter 



Pot 


No. 
plants 


Weight 


Average 
weight 


Weight 


Average 
weight 


Weight 


Average 
weight 


1-1 


5 


11.01 




15.13 




26.32 




1-2 


4 


9.07 




14.15 




23.22 




1-3 


6 


12.18 


10.75 


13.02 


14.16 


25.20 


24.91 


2-1 


6 


8.26 




9.89 




18.16 




2-2 


5 


7.45 




8.93 




16.39 




2-3 


6 


7.97 


7.89 


8.02 


8.98 


15.99 


16.84 


5-1 


7 


11.14 




12.33 




23.48 




5-2 


8 


10.67 




13.05 




23.72 




5-3 


7 


10.55 


10.79 


9.76 


11.71 


20.31 


22.50 


6-1 


6 


7.96 




8.73 




16.69 




6-2 


6 


8.26 




9.76 




18.02 




6-3 


6 


6.87 


7.69 


6.04 


8.18 


12.91 


15.87 



Table 49 — Diablo Clay Adobe, First Crop 
Oats and Bur Clover 
Planted, November 6, 1915. Harvested, May 8, 1916 
Straw Grain Total dry matter 



Pot 


No. 
plants 


Weight 


Average 
weight 


Weight 


Average 
weight 


Weight 


Average 
weight 


1-1 


Clover 3 


10.37 




11.93 




22.30 






Oats 6 


2.38 




0.14 




2.52 




1-2 


Clover 6 


8.19 




9.28 




17.47 






Oats 6 


3.48 




0.70 




4.16 




1-3 


Clover 6 


13.53 




9.81 




23.34 






Oats 6 


2.65 


13..53 


0.27 


10.71 


2.92 


24.24 


2-1 


Clover 6 


2.13 




2.57 




4.70 






Oats 6 


5.77 




1.81 




7.58 




2-2 


Clover 6 


4.24 




4.62 




8.87 






Oats 6 


4.56 




1.26 




5.82 




2-3 


Clover 6 


3.43 




4.51 




7.94 






Oats 6 


3.20 


7.75 


0.46 


5.08 


3.66 


12.85 


5-1 


Clover 6 


10.88 




9.78 




20.66 






Oats 6 


2.45 




0.27 




2.71 




,5-2 


Clover 5 


10..52 




9.32 




19.84 






Oats 6 


2.19 




0.51 




2.79 




5-3 


Clover 5 


8.31 




8.36 




16.66 






Oats 6 


3.45 


12.60 


0.66 


9.63 


4.10 


22.26 


6-1 


Clover 6 


8.90 




9.56 




18.46 






Oats 6 


3.10 




0.35 




3.45 




6-2 


Clover 6 


9.01 




5.82 




14.83 






Oats 6 


2.09 




0.52 




2.61 




6-3 


Clover 6 


6.51 




10.45 




16.97 






Oats 5 


2.33 


10.65 


0.47 


9.06 


2.80 


19.71 



/ 



1919] Pendleton: A Study of Soil Types 

Table 50 — Diablo Clat Adobe, First Crop 

PhaseoJus vulgaris 

Planted, April 4, 1916. Harvested, October 7, 1916 

Straw Grain Total dry matter 





No. 


' 


Average 


' 


Average 




Average 


Pot 


plants 


Weight 


weight 


Weight 


weight 


Weight 


weight Notes 


1-1 


8 


2.05 




0.58 




2.63 


Growth poor and 


1-2 


1 


0.94 




0.87 




1.81 


slow through- 


1-3 


12 


2.86 


1.95 


1.37 


0.94 


4.23 


2.89 out 


2-1 


3 


0.53 




0.21 




0.74 




2-2 


10 


0.83 








0.83 




2-3 


17 


1.26 


0.87 


0.11 


0.10 


1.37 


0.98 


5-1 


3 


0.53 




0.40 




0.93 




5-2 


2 


0.46 




0.41 




0.87 




5-3 






0.33 




0.27 




0.60 


6-1 


2 


0.22 








0.22 




6-2 
















6-3 


1 


0.23 


0.15 






0.23 


0.15 



Diablo clay adobe. Second crop. — The crops used in this plant- 
ing were milo (two series, one following oats and bur clover, and the 
other following oats alone), cowpeas, millet, and soy beans. The 
crop was thinned as follows: milo to eight plants, millet to twelve, 
soy beans to six, and cowpeas to six. The total dry weight (tables 
51-55) of the largest leguminous crop in this planting is about one- 
third of that of the bur clover in the first planting; though the grains 
are proportionately not nearly so much less than in the first crop. 
Soil no. 2 has the least pronounced adobe structure, but was the most 
easily puddled. The plants in one of the pots of soy beans of soil 
no. 2 were entirely killed by too much water. 

Comparing the relative growth on the soils, the notes made while 
the crops were growing coincide very closely with the dry weights. 
As to the relative crop production (fig. 28), it can be said that soils 
nos. 1 and 5 produced larger crops than soils nos. 2 and 6. Thus the 
second crop results substantiate those of the first crop. 



University of California Puhlications iii Agricultural Sciences [Vol. 3 



/O 



l5 




^rCow Peas 

CMiloA 
Millet 



Soils 



Fig. 28. Graph showing the total dry matter produced by milo (two 
series), millet, soy beans, and cowpeas on the four samples of Diablo clay 
adobe. Second crop. 



10 



VVheat 
Oafs •«- Bur CI over 
Barley 




Fig. 29. Graph showing the total dry matter produced by wheat, barley, 
oats, bur clover, Phaseolus, and oats and bur clover on the three samples of 
Altamont clay loam. First crop. 




Soy Beans B 
Soy Beans A 

Cow Ffeaa A 
Cow Peas B 

Milo A 
MiloB 



Fig. 30. Graph showing the total dry matter produced by milo (two series), 
cowpeas (two series), and soy beans (two series) on the three samples of 
Altamont clay loam. Second crop. 



1919] Pendleton: A Study of Soil Types 439 

Table 51 — Diablo Clay Adobe, Second Crop 

MiLO A (following oats) 

Planted, June 3, 1916. Harvested, November 16, 1916 

Straw Grain Total dry matter 

f ^ ^ f ^ ' ^ f ^ \ 

No. Average Average Average 

Pot plants Weight weight Weight weight Weight weight Kotes 

1-1 8 4.87 4.87 E.xeluded f rom 

1-2 8 10.00 10.00 average 

1-3 7 4.50 4.68 4.50 4.68 

2-1 8 2.59 2.59 

2-2 8 3.73 3.73 

2-3 8 2.92 3.08 2.92 3.08 

5-1 8 4.03 4.03 

5-2 6 5.13 5.13 

5-3 7 8.44 8.44 

6-1 9 3.49 3.49 

6-2 8 3.08 3.08 

6-3 8 2.98 3.18 2.98 3.18 



Table 52 — Diablo Clay Adobe, Second Crop 

MiLO B (following oats and bur clover) 

Planted, June 3, 1916. Harvested, November 16, 1916 

Straw Grain Total dry matter 

No. Average Average Average 

Pot plants Weight weight Weight weight Weight weight 

1-1 8 6.41 6.41 

1-2 8 8.78 8.78 

1-3 8 6.21 7.14 6.21 7.14 

2-1 8 3.92 3.92 

2-2 8 4.52 4.52 

2-3 8 3.63 4.02 3.63 4.02 

5-1 8 10.34 10.34 

5-2 8 6.17 6.17 

5-3 8 5.20 7.24 5.20 7.24 

6-1 8 9.29 9.29 

6-2 8 3.70 3.70 

6-3 8 4.09 5.69 4.09 5.69 



University of California PiMications in Agricultural Sciences [Vol. 3 

Table 53 — Diablo Clay Adobe, Second Ckop 

Millet (following bur clover) 

Planted, June 3, 1916. Harvested, October 6, 1917 





No. 
plants 


Straw 


Gi 


rain 


Total dry matter 


Pot 


Average 
Weight weight 


Weight 


Average 
weight 


Weight 


Average 
weight 


1-1 


12 


1.52 


1.44 




2.96 




1-2 


11 


1.34 


0.90 




2.24 




1-3 


11 


2.03 1.63 


1.15 


1.16 


3.18 


2.79 


2-1 


12 


1.26 


1.29 




2.55 




2-2 


11 


1.49 


1.32 




2.80 




2-3 


12 


0.93 1.23 


0.88 


1.16 


1.80 


2.39 


5-1 


10 


2.26 


2.19 




4.45 




5-2 


12 


3.35 


3.36 




6.71 




5-3 


12 


2.02 2.54 


1.51 


2.35 


3.53 


4.90 


6-1 


11 


1.19 


0.99 




2.18 




6-2 


12 


1.5,9 


1.23 




2.82 




6-3 


13 


1.26 1.35 


1.04 


1.09 


2.29 


2.43 



T.iBLE 54 — Diablo Clay Adobe, Second Crop 

CowPEAS (following wheat) 

Planted, August 10, 1916. Harvested, November 16, 1916 

Straw Grain Total dry matter 

No. Average Average Average 

Pot plants Weight weight Weight weight Weight weight 

1-1 7 2.66 2.66 

1-2 7 5.30 5.30 

1-3 7 3.73 3.89 3.73 3.89 

2-1 6 2.57 2.57 

2-2 6 4.24 4.24 

2-3 6 2.86 3.22 2.86 3.22 

5-1 6 2.74 2.74 

5-2 6 4.30 4.30 

5-3 6 3.64 3.56 3.64 3.56 

6-1 6 3.28 3.28 

6-2 7 4.10 4.10 

6-3 6 3.41 3.60 3.41 3.60 



1919] Fendleton: A Study of Soil Types 

Table 55 — Diablo Clay Adobe, Second Crop 

Soy Beans (following barley) 

Planted, June 6, 1916. Harvested, November 14, 1916 





No. 
plants 


Straw- 


Grain 


Total di 


■y matter 




Pot 


Weight 


Average 
weight 


"Weight 


Average 
weight 


Weight 


Average 
weight 


Notes 


1-1 


6 


8.48 




0.29 




8.77 






1-2 


6 


8.58 




0.06 




8.64 






1-3 


6 


6.87 


7.98 


0.41 


0.25 


7.28 


8.23 




2-1 


6 


2.12 








2.12 




Excluded from 


2-2 


4 


3.62 




0.40 




4.02 




average 


2-3 


5 


6.07 


4.84 


0.38 


0.39 


6.45 


5.23 




5-1 


6 


5.84 




0.16 




6.00 






5-2 


6 


7.96 




0.64 




8.60 






5-3 


6 


6.47 


6.76 


0.69 


0.49 


7.16 


7.25 




6-1 


6 


7.61 




0.24 




7.85 






6-2 


6 


7.99 




0.45 




8.43 






6-3 


6 


7.26 


7.62 


0.17 


0.28 


7.43 


7.90 





AUamoni clay loam. First crop. — The crops planted in this soil 
were wheat, barley, oats, bur clover, Phaseolus, and oats and bur 
clover together. The standard number to which the plants were 
thinned was six, except in the oats and bur clover series, where three 
plants of each were allowed to remain. 

With regard to the comparative crop producing power of these 
soils under these conditions, soil no. 4 is the best, with soil no. 3 as 
the second, and soil no. 7 was the poorest (tables 56-60, fig. 29). The 
dry weight data decidedly corroborate the impression given by the 
greenhouse appearance of the crops. However, as all the crops were 
so small on all the series, the figures do not show as much as they 
might have shown had the growth been moi'e nearly optimum for the 
several crops. 

Table 56 — Altamont Clay Loam, First Crop 

Wheat 

Planted, February 25, 1916. Harvested, July 10, 1916 





No. 
plants 


straw 


Grain 


Total dr 
Weight 


y matter 


Pot 


Weight 


Average 
weight 


Weight 


Average 
weight 


Average 
weight 


3-1 


6 


2.62 




1.23 




3.85 




3-2 


6 


2.93 




1.09 




3.92 




3-3 


6 


2.86 


2.80 


1.04 


1.12 


3.91 


3.92 


4-1 


6 


4.20 




1.78 




5.97 




4-2 


6 


4.03 




1.22 




5.25 




4-3 


6 


6.20 


4.81 


1.13 


1.38 


7.34 


6.19 


7-1 


6 


2.64 




1.11 




3.76 




7-2 


6 


2.58 




0.99 




3.64 




7-3 


6 


2.90 


2.71 


0.71 


0.93 


3.61 


3.64 



University of California Puhlications in Agricultural Sciences [Vol. 3 



Table 57 — Altamont Clay Loam, First Crop 

Barley 

Planted, April 4, 1916. Harvestetl, July 11, 1916 

Straw Grain Total dry matter 



No. 
Pot plants Weight 


Average 
weight 


Weight 


Average 
weight 


Weight 


Average 
weight 


3-1 


1.10 




0.76 




1.86 




3-2 


1.4.5 




1.40 




2.8.5 




3-3 


1.39 


1.31 


1.18 


1.11 


2.57 


2.43 


4-1 


1.99 




1.43 




3.42 




4-2 


1.90 




1..57 




3.47 




4-3 


2.39 


2.09 


1.8.5 


1.62 


4.25 


3.71 


7-1 


0.98 




0.90 




l.SS 




7-3 


1.06 


1.00 


0.,59 


0.71 


1.64 


1.71 



Table 58 — Altauont Clay Loam, First Crop 

Oats 

Planted, February 25, 1916. Harvested July 11, 1916 

Straw Grain Total dry matter 



Pot 
3-1 


No. 

plants 

6 


Weight 
1.36 


Average 
weight 


Weight 
0.38 


Average 
weight 


Weight 
1.74 


Average 
weight 


3-2 


6 


1.60 




0.67 




2.27 




3-3 


6 


1.70 


1.55 


0.47 


0.51 


2.17 


2.06 


4-1 


6 


3.05 




1.42 




4.47 




4-2 


4 


2.62 




1.13 




3.76 




4-3 


4 


3.46 


3.04 


1.81 


1.45 


5.27 


4.50 


7-1 


6 


1.21 




0.29 




1.51 




7-2 


6 


1.00 




0.42 




1.42 




7-3 


6 


0.88 


1.03 


0.35 


0.35 


1.23 


1.38 



Table 58 — Altamont Clay Loam, First Crop 

Bur Clover 

Planted, February 25, 1916. Harvested, July 8, 1916 





No. 

plants 

6 


Straw 


Gr 


in 


Total dry matter 


Pot 
3-1 


Weight 
1.50 


Average 
weight 


Weight 
1.03 


Average 
weight 


Weight 
2.53 


Average 
weight 


3-2 


6 


0.88 




1.17 




2.18 




3-3 


6 


0.63 


1.00 


1.34 


1.18 . 


1.96 


2.18 


4-1 


6 


2.48 




1.47 




3.95 




4-2 


6 


2.57 




1.57 




4.14 




4-3 


4 


2.50 


2.52 


1.31 


1.45 


3.81 


3.97 


7-1 


6 


0.47 




0.66 




1.13 




7-2 


6 


0.53 




0.24 




0.78 




7-3 


6 


0.37 


0.46 


0.20 


0.36 


0.57 


0.82 



1919] Pendleton : A Study of Soil Types 

Table 59 — Altamont Clay Loam, First Crop 

Oats and Buk Clover 

Planted, April 14, 1916. Harvested, July 8, 1916 





No. 
plants 




Sti 


•aw 


Grain 


Total dry matter 


Pot 


Average 
Weight weight Weight 


Average 
weight Weight 


Average 
weight 


3-1 


B.C. 


3 


0.98 




1.25 




2.23 






Oats 


3 


0.77 




0.10 




0.88 




3-2 


B.C. 


4 


0.79 




1.17 




1.96 






Oats 


4 


0.68 




0.22 




0.90 




3-3 


B.C. 


4 


0.48 




0.91 




1.38 






Oats 


4 


0.78 


1.49 


0.30 


1.32 


1.07 


2.81 


4-1 


B.C. 


3 


0.67 




0.32 




0.99 






Oats 


3 


2.42 




1.75 




4.17 




4-2 


B.C. 


3 


0.40 




0.62 




1.01 






Oats 


3 


2.63 




1.38 




4.01 




4-3 


B.C. 


3 


0.51 




0.21 




0.72 






Oats 


3 


2.77 


3.14 


1.09 


1.78 


3.86 


4.92 


7-1 


B.C. 


3 


0.20 




0.27 




0.47 






Oats 


3 


0.86 




0.74 




1.60 




7-2 


B.C. 


3 


0.28 




0.22 




0.50 






Oats 


3 


1.27 




0.95 




2.22 




7-3 


B.C. 


4 


0.42 




0.37 




0.74 






Oats 


2 


0.64 


1.22 


0.44 


0.98 


1.08 


2.20 



Table 60 — Altamont Clay Loam, First Crop 

Beans (Pluiseolus) 

Planted, February 25, 1916. Harvested, July 11, 1916 





No. 
plants 


Straw 


Gi 


■ain 


Total dry ; 


matter 


Pot 


Weight 


Average 
weight 


Weight 


Average 
weight 


Weight 


Average 
weight 


3-1 


6 


2.82 




0.13 




2.96 




3-2 


6 


1.24 




0.35 




1..59 




3-3 


6 


1.32 


1.79 


0.32 


0.27 


1.64 


2.06 


4-1 


5 


1.71 




0.25 




1.96 




4-2 


6 


1.41 




0.59 




2.01 




4-2 


6 


l.Sl 


1.64 


0.59 


0.48 


2.41 


2.12 


7-1 


1 


0.11 




0.09 




0.20 




7-2 


6 


0.53 








0.53 




7-3 


5 


0.63 


0.43 




0.03 


0.63 


0.46 



AHairwynt clay loam. Sec-ond crop. — A slightly different scheme 
was used in the planting of this series, only three crops were used, 
i.e., soy beans, cowpeas, and milo. Two sets of pots were planted to 
each crop, one of the two sets having previously been planted to a 
legume, and the other to a non-legume. The milo was thinned so that 



444 University of California Publications in Agricultural Sciences [Vol. 3 

one pot of each triplicate set would have 8 plants, the second of the 
set 12 plants, and the last 16 plants. It was found that the wide 
variation in the number of plants had but little effect upon the dry 
weight produced per pot (tables 61-66). The effect was indeed so 
slight that the totals were averaged up as usual. Figure 30 shows 
distinctly that there was very little variation as regards total produc- 
tion among these soils, so little as not to warrant any conclusions as 
regards substantiation of, or disagreement with, the first crop. It 
will be noticed in the second crop of the Diablo series, as well as in 
that of the Altamont series, that the maintenance of the soils under 
the same conditions for a year or more seems to bring them quite 
rapidly to an average crop producing power. 

Table 61 — Altamont Clat Loam, Second Crop 

MiLO A (following wheat) 

Planted, August 10, 1916. Harvested, November 17, 1916 

straw Grain Total dry matter 

No. Average Average Average 

Pot plants Weight weight Weight weight Weight weight Notes 

3-1 8 0.77 0.77 

3-2 12 1.01 1.01 

3-3 16 0.97 0.92 0.97 0.92 

4-1 8 1.22 1.22 

4-2 12 2.32 2.32 

4-3 16 2.08 1.87 2.08 1.87 

7-1 8 0.59 0..59 

7-2 12 0.99 1.29 

7-3 16 1.29 0.95 1.29 0.95 

Table 62 — Altamont Clay Loam, Second Crop 

MiLo B 

Planted, August 10, 1916. Harvested, November 15, 1916 

Straw Grain Total dry matter 



No. Average Average 

Pot plants Weight weight Weight weight Weight 

3-1 8 0.S2 0.82 

3-2 12 1.13 1.13 

3-3 16 1.15 1.03 1.15 

4^1 8 1.28 1.28 

4-2 12 1.82 1.82 

4-3 16 1.45 1.52 1.45 

7-1 8 0.66 0.66 

7-2 12 0.96 0.96 

7-3 16 0.92 0.85 0.92 



1919] Pendleton-: A Study of Soil Types 

Table 63 — Altamont Clay Loam, Second Crop 

COWPEAS A (following barley) 

Planted, August 10, 1916. Harvested, November 17, 1916 

Straw Grain Total dry matter 

f ^ ^ r ^ ^ r ^ \ 

No. Average Average Average 

Pot plants Weight weight Weight weight Weight weight 

3-1 6 3.48 3.48 

3-2 6 4..50 4.50 

3-3 6 3.00 3.66 3.00 3.66 

4-1 6 2.44 2.44 

4-2 6 2..59 2.59 

4-3 6 3.40 2.81 3.40 2.81 

7-1 6 2.64 2.64 

7-2 6 1.93 1.93 

7-3 6 2.15 2.24 2.15 2.24 



Pot 


plan 


3-1 


6 


3-2 


6 


3-2 


6 


4-1 


6 


4-2 


6 


4-3 


6 


7-1 


6 


7-2 


6 



Table 64 — Altamont Clay Loam, Second Crop 

CowPEAS B (following oats and bur clover) 

Planted, August 10, 1916. Harvested, November 14, 1916 

Straw Grain Total dry matter 

Average Average Average 

ts Weight weight Weight weight Weight weight 

4.16 4.16 

3.63 3.63 

2.77 3.52 2.77 3.52 

3.35 3.35 

2.70 2.70 

1.94 2.66 1.94 2.66 

1.51 1.51 

2.10 2.10 

2.85 2.15 2.85 2.15 



Table 65 — Altamont Clay Loam, Second Crop 

Sot Beans A (following oats) 

Planted, August 10, 1916. Harvested, November 17, 1916 

Straw Grain Total dry matter 

No. Average Average Average 

Pot plants Weight weight Weight weight Weight weight 

3-1 6 4.85 4.85 

3-2 6 4.25 4.25 

3-3 6 4.50 4.53 4.50 4.53 

4-1 6 3.53 3.53 

4-2 6 3.59 3.59 

4-3 6 4.88 4.00 4.88 4.00 

7-1 6 3.42 3.42 

7-2 6 3.34 3.34 

7-3 6 3.42 3.39 3.42 3.39 



446 University of California Publications in Agricultural Sciences [Vol. 3 



Table 6(5 — Altamont Clay Loam, Second Crop 

Soy Beans (following Phaseolus) 

Planted, August 10, 191<i. Harvested November 17, 1916 

Straw Grain Total dry matter 

No. Average Average Average 

Pot plants Weight weight Weight weight Weight weight Notes 

3-1 6 5.64 .5.64 

3-2 6 4.94 4.94 

3-3 6 4.84 5.14 4.84 5.14 

4-1 6 4.74 4.74 

4-2 6 4.64 4.64 

4-3 6 4.71 4.70 4.71 4.70 

7-1 6 5.25 5.25 

7-2 6 3.28 3.28 

7-3 6 4.39 4.31 4.39 4.31 



Hanford fine sandy loam. First crop. — This soil type, with sam- 
ples from nine diffei'ent localities in California, gave a much wider 
range of conditions and made a much more interesting series. Tlie 
plants used as indicators in this series were milo (twice), millet, cow- 
peas (twice), and soy beajis. The milo was thinned to eight plants 
per pot, the millet to twelve plants, and the cowpeas and soy beans 
to six plants. Set A of cowpeas, and set B of milo were unfavorably 
located, so that the results of these sets should be discounted. 

It is interesting to note the large differences in the average 
weights from soil to soil (tables 67-72, and fig. 31), as compared with 
the photographs, in which little variation appears. See especially the 
soy bean series. In this series two things are to be noted : 

1. Averages on soils nos. 15 and 25 are hardly representative be- 
cause in both cases excess moisture, from a leaky roof and too heavy 
watering, depressed growth. The tendency to become compact and to 
remain wet and cold shown by soil no. 15 aided the milo and depressed 
the soy beans. 

2. The loose, open texture of soil no. 22 seemingly favored the soy 
bean growth, though the other plants did not do as well on this soil 
as on most of the others. 



1919] 



Pendlelon : A Study of Soil Types 



Comparing the more satisfactory grains, milo A and millet, it will 
be seen that there is somewhat of a parallelism from soil to soil. The 
legumes do not always respond similarly to the grains, as in the Diablo 
first crop, yet in the Diablo second crop and the Altamont first and 
second crops the response of grain and legume seems quite similar. 
Hence, it is not safe in every case to judge as to the relationships 
shown by legumes and non-legumes. 



SqyBiade 




20 22 
6q\ Is 

Fig. 31 

Fig. 31. Graph showing the total dry matter produced by millet, milo (two 
series), cowpeas (two series), and soy beans on the nine samples of Hanford 
fine sandy loam. First crop. 



/ 



Considering all the variations, one might say that soil no. 23 was 
seemingly among the better soils, and soils nos. 16 and 22 among the 
poorer soils. Yet when discussing whether the soils be the same or 
similar, according to the criterion of the dry weight, one of the Han- 
ford groups will be similar according to one crop, and an overlapping 
group similar according to the second crop. It can be said with rea- 
sonable certainty that these Hanford soils are not closely similar to 
one another. 



University of Califoniia Publications in Agricultural Sciences [Vol. 3 



Table 67 — Hanfokd Fine Sandy Loam, First Crop 

MiLo A 

Planted, June 10, 1916. Harvested, November 18, 1916 

Straw Grain Total dry matter 

No. Average Average Average 

Pot plants Weight weight Weight weight Weight weight Notes 

14-1 8 15.34 1.5.34 Most plants bore 

14-2 8 12.50 12.50 "O grain; some 

14-3 8 10.15 12.66 10.15 12.66 ='''''° "^^^ '™" 

mature at har- 
vest. These 
cases noted, 
but no grain 
weighed. 

15-1 8 13.14 13.14 

15-2 8 14.50 14.50 

15-3 5 1.5.21 14.28 1.5.21 14.28 Not mature 

16-1 8 8.67 8.67 

16-2 8 5.86 5.86 

16-3 8 4.76 6.43 4.76 6.43 

19-1 8 7.65 7.65 

19-2 8 14.11 14.11 

19-3 8 7.01 7.01 

20-1 8 14.10 14.10 

20-2 8 10.15 10.15 

20-3 8 7.68 10.64 7.68 10.64 Not mature 

22-1 8 5.34 5.34 

22-2 8 5.88 5.88 

22-3 8 5.35 5.52 5.35 5.52 

23-1 8 8.90 8.90 Not mature 

23-2 8 10.04 10.04 Not mature 

23-3 8 8.67 9.20 8.67 9.20 

24^1 7 10.82 10.82 

24—2 8 9.92 9.92 Not mature 

24-3 8 6.01 8.92 6.01 8.92 Not mature 

2.5-1 8 11.26 11.26 

2.5-1 8 11.26 11.26 

25-2 8 5.70 5.70 

2.5-3 8 9.33 8.76 9.33 8.76 



Pendleton: A Study of Soil Type 



Table 68 — Hanford Fine Sandy Loam, First Crop 

MiLo B 

Planted, June 10, 1916. Harvested, November 20, 1916 

Straw Grain Total ary matter 

No. Average Average Average 

Pot plants Weight weight Weight weight Weight weight 

14-j. 8 10.73 10.75 

14-2 8 10.95 10.95 

14-3 8 8.84 10.18 8.84 10.18 

15-1 5 5.25 5.25 

15-2 4 4.62 4.62 

15-3 2 3.92 4.60 3.92 4.60 

16-1 7 7.36 7.36 

16-2 2 2.18 2.18 

16-3 4 2.74 4.09 2.74 4.09 

19-1 3 3.73 3.73 

19-2 8 4.79 4.79 

19-3 8 9.60 6.04 9.60 6.04 

20-1 8 8.14 8.14 

20-2 8 3.23 ...... 3.23 

20-3 8 3.22 4.86 3.22 4.86 

22-1 6 4.74 4.74 

22-2 5 3.01 3.01 

22-3 7 3.19 3.64 3.19 3.64 

23-1 8 5.68 5.68 

23-2 5 7.72 7.72 

23-3 8 6.93 6.78 6.93 6.78 

24-1 3 3.16 3.16 

24-2 6 5.64 5.64 

24-3 6 3.26 4.02 3.26 4.02 

2.5-1 4 3.07 3.07 

25-2 3 2.34 2.34 

25-3 8 4.34 3.25 4.34 3.25 



University of California Publications in Agricultural Sciences [Vol. 3 



Table 69 — Hanford Fine Sandy Loam, First Crop 
Millet 

Planted, June 10, 1916. Harvested: Nos. 15-25, September 20, 1916; No. 14, 
October 6, 1916 

Straw Grain Total dry matter 



Pot 
14-1 


No. 
plants 

12 


Weight 
3.75 


Average 
weight 


Weight 
2.90 


Average 
weight 


Weight 
6.65 


Average 
weight 


Notes 


14-2 


13 


4.23 




2.95 




7.18 






14-3 


14 


3.46 


3.81 


2.01 


2.62 


5.47 


6.43 




15-1 


12 


3.63 




1.02 




4.65 






15-2 


12 


4.63 




1.31 




5.93 






15-3 


12 


3.86 


4.04 


1.12 


1.15 


4.98 


5.19 




16-1 


13 


1.96 




0.74 




2.7.0 






16-2 


12 


3.10 




1.81 




4.91 






16-3 


12 


1.52 


2.19 


0.73 


1.09 


2.25 


3.29 




19-1 


12 


1.85 




0.73 




2.58 




Seed immature 


19-2 


12 


1.71 




0.76 




2.48 




Poor. Lack of 


19-3 


12 


2.00 


1.85 


0.69 


0.73 


2.69 


2.58 


drainage? 


20-1 


12 


6.54 




2.78 




9.32 




Possible error in 


20-2 
20-3 


12 
12 


1.70 
6.57 


6.55 


1.01 
2.21 


2.50 


2.71 
8.78 


9.05 


grain weight. 
Original shows 
6 grams 


22-1 


12 


2.04 




0.65 




2.69 






22-2 


12 


2.32 




0.68 




3.00 






22-3 


12 


4.44 


2.93 


1.90 


1.08 


6.34 


4.01 




23-1 


12 


6.12 




1.21 




7.33 






23-2 


12 


6.13 




2.14 




8.27 






23-3 


12 


6.01 


6.08 


1.97 


1.78 


7.99 


7.86 




24-1 


12 


4.18 




1.50 




5.69 






24-2 


12 


2.80 




0.91 




3.70 






24-3 


11 


4.89 


3.96 


2.08 


1.50 


6.98 


5.46 




25-1 


12 


2.06 




0.77 




2.83 






25-2 


12 


2.01 




0.51 




2.52 






25-3 


12 


4.31 


2.79 


2.15 


1.14 


6.46 


3.94 





1919 J Pendleton: A Study of Soil Types 



Table 70 — HANroRD Pine Sandy Loam, First Crop 

Soy Beans 

Planted, June 10, 1916. Harvested, December 11, 1916 

Straw Beans Total dry matter 

No. Average Average Average 

Pot plants Weight weight Weight weight Weight weight Notes 

14-1 6 16.69 16.69 Immature seed 

14-2 6 16.28 16.28 Immature seed 

14-3 6 11.89 14.95 0.44 0.15 12.33 15.10 Immature seed 

15-1 6 14.08 0.23 14.31 Immature seed 

15-2 6 5.17 5.17 Immature seed 

15-3 6 6.53 8.59 0.08 6.53 8.67 Immature seed 

16-1 6 12.63 0.32 12.95 Immature seed 

16-2 6 14.60 14.60 Immature seed 

16-3 6 16.60 14.61 0.11 16.60 14.72 Immature seed 

19-1 6 12.84 12.84 Immature seed 

19-2 6 11.68 11.68 Immature seed 

19-3 6 16.03 13.52 16.03 13.52 Immature seed 

20-1 6 8.77 8.77 Immature seed 

20-2 6 16.33 16.33 Immature seed 

20-3 6 14.27 13.13 14.27 13.13 Immature seed 

22-1 6 20.28 20.28 Immature seed 

22-2 6 19.44 19.44 Immature seed 

22-3 6 15.60 18.44 15.60 18.44 Immature seed 

23-1 6 21.42 21.42 No seed 

23-2 6 20.75 20.75 No seed 

23-3 6 20.68 20.95 20.68 20.95 Immature seed 

24—1 6 17.37 17.37 Immature seed 

24-2 6 21.24 21.24 Immature seed 

24-3 6 13.70 17.43 13.70 17.43 Immature seed 

2.5-1 6 5.53 5.53 Rained on; exclud- 
ed from average 

2.5-2 6 17.85 17.85 No seed 

25-3 6 21.58 19.71 21.58 19.71 Immature seed 



University of California PuiUcations in Agricultural Sciences [Vol. 3 



Table 71 — Hanford Fine Sandy Loam, First Crop 

cowpeas a 

Planted, June 10, 1916. Harvested, October 21, 1916 

Straw Beans Total dry matter 



Pot 


No. 
plants 


Weight 


Average 
weight 


Weight 


Average 
weight 


Weight 


Average 
weight 


Notes 


14-1 


6 


2.99 




0.93 




3.92 






14-2 


6 


3.52 








3.52 






14-3 


6 


4.18 


3.56 






4.18 


3.87 




15-1 


















15-2 


















15-3 


















16-1 


1 


2.98 








2.98 




Immature seed 


16-2 


3 


3.05 




1.50 




4.58 






16-3 


4 


2.60 


2.88 


2.16 


1.22 


4.76 


4.10 




19-1 


6 


1.49 




0.27 




1.77 






19-2 


6 


1..54 




0.28 




1.82 






19-3 


2 


1.10 


1.38 


0.47 


0.34 


1.57 


1.72 




20-1 


6 


2.86 




0.32 




3.18 






20-2 


6 


2.08 




0.58 




2.66 






20-3 


6 


2.99 


2.64 


0.33 


0.41 


3.32 


3.05 




22-1 


5 


1.80 




0.23 




2.02 






22-2 


















22-3 


2 


1.96 


1.88 


0.39 


0.31 


2.35 


2.19 




23-1 


















23-2 


1 


1.80 




0.76 




2.57 






23-3 






1.80 




0.76 




2.57 




24-1 


2 


1.06 




0.25 




1.30 






24-2 


1 


1.80 




1.29 




3.09 






24-3 


2 


1.75 


1.54 


0.45 


0.66 


2.20 


2.20 




25-1 


3 


2.74 




2.03 




4.78 






25-2 


1 


1.88 




2.28 




4.17 






25-3 


2 


2.12 


2.25 


1.24 


1.85 


3.36 


4.10 





1919] Pendleton: A Study of Soil Typex 

Table 72 — Hanford Fine Sandt Loam. First Crop 

cowpeas b 

Planted, June 10, 1916. Harvested, November 21, 1916 

Straw Beans Total dry matter 

No. Average Average Average 

Pot plants Weight weight Weight weight Weight weight Notes 

14-1 6 3.94 3.94 

14^2 6 5.93 5.92 

14-3 6 3.32 4..39 3.32 4.39 

15-1 6 7.24 7.24 

15-2 6 5.34 5.34 

15-3 6 4.61 5.74 4.6x 5.74 

16-1 6 5.90 5.90 

16-2 6 5.S2 5.82 

16-3 6 3.65 5.12 3.65 5.12 

19-1 6 3.34 3.34 

19-2 6 3.38 3.38 

19-3 6 3.87 3.53 3.87 3.53 1 died early 

20-1 6 . '3.09 3.09 

20-2 6 3.15 3.15 1 died early 

20-3 6 2.80 3.01 2.80 3.01 

22-1 6 3.12 3.12 

22-2 6 3.61 3.61 

22-3 6 4.92 3.88 4.92 3.88 

23-1 6 4.59 4.59 

23-2 6 6.04 6.04 

23-3 6 4.08 4.90 4.08 4.90 

24-1 6 3.81 3.81 

24-2 ■ 5 4.28 4.28 

24-3 6 6.42 4:84 ' 6.42 4.84 

25-1 5 4.17 4.17 

25-2 6 3.93 3.93 1 died early 

2.5-3 6 4.86 4.32 4.86 4.32 



Hanford fi.ne sandy loam. Second crop. — Barley (twice), oats, 
wheat, bur clover {Medicago sp.), and Melilotus indica were the indi- 
cator crops used when the Hanford soils were planted the second time. 
In all cases a sufficient quantity of seed was used to insure the growth 
of more plants than would be raised to maturity. Later the plants 
in each pot were thinned to six in number, good specimens and well 



454 University of California Publications in Agricultural Sciences [Vol. 3 

spaced. The final number of plants varied, but was almost alwaj'S six. 
An attempt was made to reduce at least partially the shading and 
exposure effects. The pots were periodically changed from position 
to position on the bench. 

The total dry weights produced on the several soils are interesting 
(tables 73-78, and fig. 33). The grains gave more uniform results in 
this crop than in the first. Soils nos. 14 and 23 show the best crops, 
and they are the ones that have the highest amounts of total nitrogen. 
The legumes selected must have been particularly well adapted to the 
growing conditions and the soils, because the growth was enormous. 
In the amount of dry matter produced the parallelism between the 
two legumes from soil to soil is close. It is noteworth.y that soil no. 14, 




Wheat 
Bur Clover 
Oots 
^\^eli lotus 
25 Bar lev, 



ng.3£ 

Fig. 32. Graph showing the total dry matter produced by barle.v, wheat, 
oats, rye, bur clover, and Melilotus indica on the eight samples of San Joaquin 
sandy loam. First and only crop. 



which showed the highest total nitrogen and produced the most dry 
matter from the grains, gave the poorest crop of legumes. The notes 
taken during the growing period show that the relative appearances 
quite early and throughout the period of growth are usually a good 
index to the relative amounts of dry matter pi-oduced. This is so, 
even though the photographs of the mature plants do not show dif- 
ferences nearly as great in magnitude as do the dry weights. 

This type does not show any marked tendency for the several soils 
to approach a more uniform crop producing capacity through being 
kept under the same conditions. In fact, the second crop shows 
greater variations than the first. And this type does not show that 
these nine soils, mapped under a single type name, are closely similar 
to one another in crop producing power. 



1919] Pendleton: A Study of Soil Types 



Table 73 — Hanford Fine Sandy Loam, Second Crop 

Wheat (following millet) 
Planted, October 30, 1916. Harvested, June 21, 1917 
Straw Grain Total dry matter 



Pot 


plants 


Weight 


14-1 


6 


10.75 


14-2 


5 


5.20 


14-3 


6 


14.85 


15-1 


6 


3.55 


15-2 


6 


4.85 


15-3 


6 


2.80 


16-1 


6 


3.20 


16-2 


6 


8.20 



19-1 


6 


2.80 


19-2 


6 


2.80 


19-3 


6 


2.20 


20-1 


6 


5.45 


20-2 


6 


4.05 


20-3 


6 


21.35 


22-1 


6 


4.15 


22-2 


6 


3.95 


22-3 


6 


4.45 


23-1 


6 


4.90 


23-2 


6 


4.75 


23-3 


6 


3.75 


24-1 


6 


18.60 


24-2 


6 


3.20 


24-3 


6 


23.75 


25-1 


6 


15.75 


25-2 


6 


2.50 


2.5-3 


6 


2.25 



Weight 


Average 
weight 


Weight 


Average 
weight 


Notes 


3.55 




14.30 






2.10 




7,30 






6.45 


4.03 


21.30 


14.30 




1.30 




4.65 






1.50 




,6.35 






1.10 


1.30 


3.90 


4.96 




0.95 




4.15 






3.70 




11.90 




Rained on, exclud- 
ed from average 


0.70 


0.82 


3.50 


3.82 




0.75 




3.55 






0.65 




3.45 






0.60 


0.66 


2.80 


3.26 




2.80 




8.25 






1.55 




5.60 






12.90 


2.17 


34.25 


6.90 


Eained on, exclud- 
ed from average 


0.90 




5.05 






0.40 




4.35 






0.90 


0.73 


5.35 


4.92 




1.60 




6.50 






1.60 




6.35 






1.10 


1.43 


4.85 


5.90 




8.30 




26.90 




Eained on, exclud- 
ed from average 


0.90 




4.10 




Rained on, exclud- 
ed from average 


5.40 


0.90 


29.15 


4.10 


Rained on, exclud- 
ed from average 


9.05 




24.80 






0.35 




2.85 






0.80 


0.57 


3.05 


2.95 





University of California Publications in Agricultural Sciences [Vol. 

Table 74 — Hanpord Fine Sandy Loam, Second Crop 

Oats (following milo A) 
Planted, November 22, 1916. Harvested, June 18, 1917 
Straw Grain Total dry matter 



Pot 


No. 
plants 


Weight 


Average 
weight 


Weight 


Average 
weight 


Weight 


Average 
weight 


Notes 


14-1 


6 


3.80 




2.90 




6.70 






14-2 


6 


3.40 




1.85 




5.25 






14-3 


6 


3.20 


3.47 


2.40 


2.38 


5.65 


5.86 




15-1 


6 


2.45 




1.35 




3.80 






15-2 


6 


1.75 




1.25 




3.00 






15-3 


6 


2.00 


2.06 


1.50 


1.36 


3.50 


3.43 




16-1 


6 


11.15 




8.40 




19. .55 




Rained on, exclud- 
ed from average 


16-2 


6 


2.M 




2.30 




4.45 




Pot saturated with 
soluble salts, ex- 
cluded from av- 
erage 


16-3 


6 


1.15 


2.15 


0.70 


2.30 


1.85 


4.45 




19-1 


6 


1.75 




1.25 




3.00 






19-2 


6 


4.55 




2.95 




7.50 






19-3 


6 


1.35 


2.55 


0.95 


1.72 


2.30 


4.27 





20-2 


6 


1.55 


20-3 


6 


1.65 


22-1 


6 


1.65 


22-2 


6 


2.10 


22-3 


6 


2.50 


23-1 


6 


2.70 


23-2 


6 


1.90 


23-3 


6 


3.20 


24-1 


6 


4.80 


24-2 


6 


16.75 



25-1 


6 


1.95 


25-3 


6 


2.25 


25-2 


6 


1.80 



6.30 16.75 Rained on, exclud- 

ed from average 
1.05 2.60 

1.00 1.02 2.65 2.62 

1.10 2.75 

1.15 3.25 

1.50 1.25 4.00 3.33 

1..55 4.25 

1.60 3..50 

2.00 1.71 5.20 4.32 

3.10 7.90 

9.80 26.55 Rained on, exclud- 

ed from average 

2..35 2.73 5.70 6.S0 

1.30 3.25 

1.40 1.30 3.65 3.30 

1.20 3.00 



1919] Pendleton : A Study of Soil Types 



Table 75 — Hanford Fine Sandy Loam, Second Crop 

Barley A (following eowpeas A) 

Planted, October 30, 1916. Harvested, May 20, 1917 

Straw Grain Total dry matter 



Pot 


plants 


Weight 


14-1 


6 


4.75 


14-2 


6 


9.22 


14-3 


6 


11.97 


13-1 


6 


15.47 


13-2 


6 


3.78 


15-3 


6 


5.00 


16-1 


6 


7.28 


16-2 


6 


2.55 


16-3 


6 


2.20 


19-1 


6 


2.82 


19-2 


6 


2.39 


19-3 


6 


2.89 


20-1 


6 


3.57 


20-2 


6 


3.32 


20-3 


6 


19.35 



22-1 


6 


2.73 


22-2 


6 


5.89 


22-3 


6 


3.69 


23-1 


6 


5.29 


23-2 


6 


6.19 


23-3 


6 


7.98 


24-1 


6 


3.07 


24-2 


6 


21.85 


24-3 


6 


4.73 


2.3-1 


6 


2.47 


25-2 


6 


Lost 



Weight 


Average 
weight 


Weight 


Average 
weight 


4.30 




9.05 




9.00 




18.22 




10.85 


8.05 


22.82 


16.69 


15.30 




30.77 




3.29 




7.07 




4.12 


3.70 


9.12 


S.09 


6.42 




13.70 




2.55 




.5.10 




1.71 


3.56 


3.91 


7.57 


1.80 




4.62 




1.91 




4.30 




2.25 


1.98 


5.14 


4.68 


2.90 




6.47 




2.80 




6.12 




7.45 


2.85 


26.70 


6.29 


2.07 




4.80 




3.53 




9.42 




2.73 


2.78 


6.42 


6.88 


3.35 




8.64 




4.23 




10.42 




4.20 


3.93 


12.18 


10.41 


2.54 




5.61 




9.75 




31.60 




3.57 


3.05 


8.30 


6.95 



Rained on, exclud- 
ed from average 



6.29 Rained on, exclud- 
ed from average 



Rained on, e.xcliid- 
ed from average 

Pot broken, ex- 
cluded from av- 
erage 



University of California Publications in Agricultural Sciences [Vol. 3 



Table 76 — Hanford Fine Sandy Loam, Second Crop 

Barley B (following soy beans) 

Planted, January 31, 1917. Harvested, June 21, 1917 

Straw Grain Total dry matter 



Pot 


No. 
plants 


Weight 


Average 
weight 


Weight 


Average 
weight 


Weight 


Average 
weight 


14-1 


6 


9.55 




6.80 




16.35 




14-2 


6 


6.05 




5.40 




11.45 




14-3 


6 


3.80 


6.47 


2.10 


4.76 


5.90 


11.23 


15-1 


6 


3.50 




2.80 




6.30 




15-2 


6 


3.20 




1.70 




4.90 




15-3 


6 


4.05 


3.58 


2.60 


2.36 


6.65 


5.95 


16-1 


6 


3.10 




1.45 




4.55 




16-2 


6 


9.20 




8.20 




17.40 





19-1 


6 


3.05 


19-2 


6 


2.65 


19-3 


6 


2.15 


20-1 


6 


3.35 


20-2 


6 


4.20 


20-3 


6 


2.55 


22-1 


6 


2.05 


22-2 


6 


2.90 


22-3 


6 


3.15 


23-1 


6 


3.10 


23-2 


6 


3.10 


23-3 


6 


3.40 


24-1 


6 


3.10 


24-2 


6 


10.10 



2.5-1 


6 


3.35 


25-2 


6 


3.10 


25-3 


6 


4.70 



Rained on, exclud- 
ed from average 

4.50 1.45 11.85 4.55 Rained on, exclud- 
ed from average 

0.80 3.85 

2.20 4.85 

1.85 1.61 4.00 4.23 

2.60 5.95 

3.20 7.40 

2.15 2.65 4.70 6.02 

1.75 3.80 

2.35 5.25 

2.25 2.12 .5.40 4.82 

2.05 5.15 

2.95 6.05 

2.75 2.58 6.15 5.78 

1.45 3.70 

5.80 15.90 Rained on, exclud- 

ed from average 
2.35 1.90 5.40 4.55 

2.90 6.25 

1.85 4.95 

4.60 3.12 9.30 6.83 



1919] Pendleton: A Study of Soil Types 



Table 77 — Hanford Fine Sandy Loam, Second Crop 

Melilotus indica (following cowpeas B) 
Planted, November 22, 1916. Harvested, June 21, 1917 





No. 
plants 


Straw 


Unhiilled seed 


Total dry matter 


Pot 


Weight 


Average 
weight 


Weight 


Average 
weight 


Weight 


Average 
weight Notes 


14-1 


6 


17.00 




15.80 




32.80 




14-3 


6 


13.25 




16.45 




29.70 




14-3 


6 


4.40 


15.12 


3.10 


16.12 


7.50 


31.25 Excluded from 
average 


15-1 


6 


35.00 




34.75 




69.75 




15-2 


6 


24.85 




27.28 




52.05 




15-3 


6 


28.95 


29.60 


32.70 


31.58 


61.65 


61.15 


16-1 


5 


23.50 




24.90 




48.40 




16-2 


6 


30.80 




25.50 




56.30 




16-3 


6 


23.65 


25.98 


25.70 


25.37 


49.35 


51.35 


19-1 


6 


20.50 




18.35 




38.85 




19-2 


6 


26.90 




23.20 




.50.10 




19-3 


6 


26.20 


24.53 


27.40 


22.98 


53.60 


47.52 


20-1 


6 


20.55 




17.80 




38.35 




20-2 


6 


20.75 




21.20 




41.95 




20-3 


6 


28.85 


23.38 


26.05 


21.68 


54.90 


45.07 


22-1 


6 


28.00 




28.10 




56.10 




22-2 


6 


32.30 




34.20 




66.50 




22-3 


6 


28.25 


29.52 


31.85 


31.38 


60.10 


60.90 


23-1 


6 


38.05 




34.25 




72.30 




23-2 


6 


34.40 




36..55 




70.95 




23-3 


6 


32.25 


34.90 


32.35 


34.38 


64.60 


69.28 


24-1 


6 


37.35 




31.40 




68.75 




24-2 


6 


25.90 




28.10 




54.00 




24-3 


6 


29.05 


30.77 


30.15 


29.88 


59.20 


60.65 


25-1 


6 


25.35 




30.45 




55.80 




25-2 


6 


33.90 




35.90 




69.80 




25-3 


6 


32.10 


30.45 


36.65 


34.33 


68.75 


64.78 



University of California Publications in Agricultural Sciences [Vol. 3 

Table 78 — Hanfokd Fine Sandy Loam, Second Crop 

Bur Clover (following milo B) 

Planted, November 22, 1916. Harvested, June 2.5, 1917 

Straw Burs Total dry matter 



Pot 


No, 
plants 


Weight 


Average 
weight 


Weight 


Average 
■weight 


Weight 


Average 
weight 


14-1 


7 


6.70 




17.55 




24.25 




14-2 


6 


7.00 




16.85 




23.85 




14-3 


6 


6.10 


6.60 


14.50 


16.30 


20.60 


22.90 


15-1 


6 


13.30 




29.10 




42.40 




15-2 


6 


14.45 




33.10 




47..55 




15-3 


6 


17.10 


14.95 


26.65 


29.62 


43.75 


44.56 


16-1 


6 


8.85 




15.40 




24.25 




16-2 


6 


12.25 




29.60 




41.85 




16-3 


6 


10.05 


10.38 


21 .90 


22.30 


31.95 


32.68 


19-1 


6 


9.90 




19.90 




29.80 




19-2 


6 


7.70 




17.80 




25.50 




19-3 


6 


8.20 


8.60 


22.40 


20.03 


30.60 


28.63 


20-1 


6 


7.90 




22.50 




30.40 




20-2 


6 


9.75 




23.30 




33.05 




20-3 


6 


8.70 


8.78 


20.50 


22.10 


29.20 


30.88 


22-1 


6 


15.90 




38.00 




53.90 




22-2 


6 


13.20 




23.40 




36.60 




22-3 


6 


14.50 


14.53 


31.30 


30.90 


45.80 


45.43 


23-1 


6 


14.45 




37.40 




51.85 




23-2 


6 


13..55 




27.30 




40.85 




23-3 


6 


12.05 


13.35 


28.00 


30.90 


40.05 


44.25 


24-1 


6 


10.60 




24.30 




34.90 




24-2 


6 


12.10 




34.10 




46.20 




24-3 


6 


10.25 


10.98 


24.00 


27.46 


34.25 


38.45 


25-1 


6 


17.90 




40.00 




57.90 




25-2 


6 


14.60 




30.80 




45.40 




25-3 


6 


13.35 


15.28 


26.40 


32.40 


39.75 


47.68 



San Joaquin sandy loam. — The samples of tliis type were the last 
to be weighed into pots and planted, because of the lack of available 
greenhouse space; therefore the time allowed for the growing of but 
one crop, instead of two, on each pot of soil. The crops used were 
wheat, barley, rye, oats, bur clover {Medicago sp.), and Melilotus 
indic-a. As was done for the other types, an excess of seed was 
planted. When the plants were well established, thinning reduced 
the number to six plants per pot. 

Since the specific gravity of this soil was high, because of the large 
amount of quartz and the small amount of organic matter in its com- 
position, six kilos of soil, instead of five, were weighed out into each 
pot. The samples of this type have the very annoying peculiarities 
of becoming very mushy if an excess of water be added, and of setting 



1919] Pendleton: A Study of Soil Types 461 

with a very hard surface on drying. This makes the soils hard to 
handle in greenhouse pot culture work. 

The variation in crop growth from soil to soil, as shown by the 
total drj' matter produced (tables 79-84 and fig. 32), is rather 
marked. That the several samj)les do not show equal crop producing 
powers is very evident, though with regard to the several indicator 
crops the soils would frequently not maintain the same order. Soil 
no. 26 gave the poorest yields with all six crops. Except for wheat, 
the soils nos. 10, 11, and 12 gave low yields with both the grains and 
the legumes. It is interesting to note that wheat gave relatively high 
yields with a number of the soils, and wheat has probably been raised 
on these soils more than any other one crop. This series shows that, 
as far as the samples represent the type and the crops used represent 
crops as a whole, the soils mapped under a given type name are not 
closely similar in crop producing power under greenhouse conditions. 

Table 79 — San Joaquin Sandy Loam 

Rye 

Planted, November 22, 1916. Harvested, June 21, 1917 





No. 
plants 


Straw 


Gra 


in 


Total dry 


matter 


Pot 


Weight 


Average 
weight 


Weight 


Average 
weight 


Weight 


Average 
weight Not( 


10-1 


6 


1.70 




0.30 




2.00 




10-2 


6 


2.30 




0.35 




2.65 




10-3 


6 


2.05 


2.02 


0.65 


0.43 


2.70 


2.45 


11-1 


6 


3.1:) 




0.70 




3.85 




11-2 


6 


2.25 




0.70 




2.95 




11-3 


4 


3.20 


2.87 


0.70 


0.70 


3.90 


3.57 


12-1 


6 


1.65 




0.45 




2.10 




12-2 


6 


2.45 




0.85 




3.30 




12-3 


6 


2.40 


2.17 


0.65 


0.65 


3.05 


2.82 


13-1 


6 


4.20 




1.25 




5.45 




13-2 


6 


4.30 




0.80 




5.10 




13-3 


6 


3.75 


4.08 


1.60 


1.22 


5.35 


5.30 


17-1 


6 


7.55 




1.60 




9.15 


Rained on 


17-2 


6 


1.95 




0.55 




2.50 




17-3 


6 


1.80 


1.87 


0.45 


0.50 


2.25 


2.37 


18-1 


6 


2.35 




0.85 




3.20 




18-2 


6 


0.90 




0.30 




1.20 




18-3 


6 


3.70 


2.32 


1.20 


0.78 


4.90 


3.10 


21-1 


6 


2.20 




0.80 




3.00 




21-2 


6 


2.70 




0.95 




3.65 




21-3 


6 


6.55 


2.45 


2.35 


ft.87 


8.90 


3.33 Rained on 


26-1 


6 


1..50 




0.60 




2.10 




26-2 


6 


2.55 




0.75 




3.30 




26-3 


6 


2.50 


2.18 


0.70 


0.68 


3.20 


2.87 



University of California Publications in Agricultural Sciences [Vol. 3 




14 15 16 19 20 22 23 24 25 Soils 

Fig. 33. Graph showing the total dry matter produced by wheat, oats, 

barley (two series), bur clover, and Melilotus iiidica on the nine samples of 

Hanford fine sandy loam. Second crop. 



1919] Pendleton: A Study of Soil Types 



Table 80 — San Joaquin Sandy Loam 
Barley 
Planted, October 30, 1916. Harvested, June 17, 1917 
Straw Grain Total dry matter 



Pot 


No. 
plants 


Weight 


Average 
weight 


Weight 


Average 
weight 


Weight 


Average 

weight Notes 


10-1 


6 


2.93 




0.92 




3.85 




10-2 


6 


1.87 




0.81 




2.68 




10-3 


6 


1.47 


2.09 


0.85 


0.86 


2.32 


2.95 


11-1 


6 


1.91 




0.66 




2.57 




11-2 


6 


2.02 




1.28 




3.30 




11-3 


6 


2.97 


2.30 


0.90 


0.95 


3.87 


3.25 


12-1 


6 


10.27 




4.95 




15.22 


Eained on; exclud- 


12-2 


6 


3.60 




1.32 




4.92 


ed from average 


12-3 


6 


3.49 


3.54 


0.43 


0.87 


3.92 


4.42 


13-1 


6 


2.14 




1.46 




3.60 




13-2 


6 


3.19 




1.78 




4.97 




13-3 


6 


3.28 


2.87 


1.77 


1.67 


5.05 


4.53 


17-1 


6 


3.89 




2.17 




6.06 




17-2 


6 


3.74 




1.80 




5.54 




17-3 


6 


2.44 


3.35 


0.80 


1..59 


3.24 


4.95 


18-1 


6 


4.65 




1.93 




6.58 




18-2 


6 


3.74 




1.94 




5.68 




18-3 


6 


5.61 


4.66 


2.,34 


2.07 


7.95 


6.74 


21-1 


6 


2.05 




1.53 




3. .58 




21-2 


6 


2.10 




1.80 




3.90 




21-3 


6 


3.81 


2.65 


2.33 


1.88 


6.14 


4.54 


26-1 


6 


1.12 




0.63 




1.75 




26-2 


6 


1.08 




0.41 




1.49 




26-3 


6 


1.20 


1.13 


0.70 


0.58 


1.90 


1.71 



University of California Puhlications in Agricultural Sciences [Vol. 3 



Table 81 — San Joaquin Sandy Loam 

Wheat 

Planted, October 30, 1916. Harvested, June 21, 1917 

Straw Grain Total dry matter 



Pot 


plants 


Weight 


10-1 


6 


3.59 


10-2 


6 


3.45 


10-3 


6 


6.35 


11-1 


6 


5.60 


11-2 


6 


2.75 


11-3 


6 


3.45 


12-1 


6 


6.85 


12-2 


6 


7.50 


12-3 


6 


4.45 


13-1 


6 


3.90 


13-2 


6 


3.25 


13-2 


6 


3.95 


17-1 


6 


2.70 


17-2 


6 


1.20 


17-3 


6 


2.75 


18-1 


6 


.5.90 


lS-2 


6 


7.90 


18-3 


6 


5.00 


21-1 


6 


3.10 


21-2 


5 


4.30 


21-3 


6 


8.40 


26-1 


6 


2.35 


26-2 


6 


0.40 


26-3 


6 


2.60 



verage Average Average 

veight Weight weight Weight weight Note 

0.85 4.80 

0.45 3.90 

4.58 0.75 0.68 7.10 5.26 

1.15 6.75 

0.60 3.35 

3.93 0.70 0.81 4.15 4.75 

2.00 8.85 

1.35 8.85 

6.27 1.35 1.56 5.80 7.83 

0.85 4.75 

0.45 3.70 

3.70 0.75 0.68 4.70 4.38 

0.25 2.95 

0.45 1.65 

2.21 none 0.23 2.75 2.45 

1.50 7.40 

2.40 10.30 Rained on 

5.45 1.00 1.25 6.00 6.70 

1.05 4.15 

0.75 5.05 

3.70 2.45 0.90 10.85 4.60 Rained on 

0.55 2.90 

none 0.40 Rained on 

2.47 0.35 0.45 2.95 2.92 



1919] Pendleton: A Study of Soil Types 



Table 82 — San Joaquin Sandy Loam 

Oats 

Planted, November 22, 1916. Harvested, June 17, 1917 

Straw Grain Total dry matter 



Pot 


No. 
plants 


Weight 


Average 
weight 


Weight 


Average 
weight 


Weight 


Average 
weight 


10-1 


6 


2.25 




0.90 




3.15 




10-2 


6 


3.65 




1.90 




5.55 




10-3 


6 


1.70 


2.53 


0.50 


1.10 


2.20 


3.63 


11-1 


6 


2.25 




1.25 




3.50 




11-2 


6 


1.75 




0.95 




2.70 




11-3 


6 


2.10 


2.03 


1.00 


1.07 


3.10 


3.10 


12-1 


6 


1.70 




0.90 




2.60 




12-2 


6 


2.40 




1.00 




3.40 




12-3 


6 


2.35 


2.15 


1.05 


0.98 


3.40 


3.13 


13-1 


6 


2.25 




1.20 




3.45 




13-2 


6 


2.40 




1.10 




3.50 




13-3 


6 


2.70 


2.45 


1.70 


1.33 


4.40 


3.78 


17-1 


6 


0.80 




0.55 




1.35 




17-2 


6 


1.50 




0.90 




2.40 




17-3 


6 


1.25 


1.90 


0.70 


0.72 


1.95 


1.90 


18-1 


6 


1.70 




1.00 




2.70 




18-2 


6 


1.15 




0.60 




1.75 




lS-3 


6 


1.10 


1.32 


0.50 


0.70 


1.60 


2.02 


21-1 


6 


1.85 




0.95 




2.80 




21-2 


6 


2.35 




1.05 




3.40 




21-3 


6 


1.00 


1.73 


0.55 


0.S5 


1.55 


2.58 


26-1 


6 


1 .55 




0.60 




2.15 




26-2 


6 


1.35 




0.80 




2.15 




26-3 


6 


1.65 


1.52 


0.70 


0.70 


2.35 


2.22 



University of Catifoniia PuhUcations in Agricultural Sciences [Vol.3 









Table 83- 


-San Joaquin 


Sakdy 


Loam 










Bur 


Clover 








Planted, 


Novembei 


22, 1916. Hai 


vested, 


June 17, 1917 




No. 
plants 


Straw 


Seedi 


n bui-s 


Total dry matter 


Pot 


Weigh 


Average 
weight 


Weight 


Average 
weight 


Weight 


Average 

weight Notes 


10-1 


6 


0.50 




0.95 




1.45 




10-2 


6 


1..50 




1.65 




3.15 




10-3 


6 


0..50 


0.83 


1.75 


1.45 


2.25 


2.28 


11-1 


6 


0.90 




2.00 




2.90 




11-2 


6 


0.2.5 




1.00 




1.25 




11-3 


6 


0.30 


0.4S 


1.10 


1.37 


1.40 


1.85 


12-1 


6 


0.90 




3.00 




3.90 




12-2 


6 


2.15 




5.30 




7.45 




12-3 


6 


1.50 


1.52 


1.90 


3.40 


3.40 


4.92 


13-1 


6 


1.55 




3.45 




5.00 




13-2 


6 


0.75 




2.80 




3.55 




13-3 


6 


4.35 


1.15 


5.70 


3.12 


9.05 


4.27 Excluded from av 
erage 


17-1 


6 


0.70 




2.05 




2.75 




17-2 


6 


2.35 




3.85 




6.20 


Excluded from av 
erage 



18-1 


6 


1.20 




3.40 




4.60 






18-2 


6 


3.25 




6.65 




9.90 




Excluded from av 
erage 


18-3 


6 


1.80 


1.50 


4.85 


4.12 


6.65 


5.62 




21-1 


6 


3.35 




3.70 




7.05 






21-2 


6 


2.00 




3.90 




5.90 






21-3 


6 


1.75 


2.37 


5.15 


4.25 


6.90 


6.62 




26-1 


6 


0.60 




1.45 




2.05 






26-2 


6 


1.20 




2.75 




3.95 






26-3 


6 


0.40 


0.73 


1.30 


1.83 


1.70 


2.56 





1919] Pendleton: A Study of Soil Types 

Table 84 — San Joaquin Sandy Loam 

Melilotus indica 

Planted, November 22, 1916. Harvested, June 21, 1917. 

Straw Unhulled seed Total dry matter 



Pot 


No. 
plants 


Weight 


Average 
weight 


Weight 


Average 
weight 


Weight 


Averag 
weight 


10-1 


6 


1.20 




1.20 




2.40 




10-2 


6 


1.03 




0.92 




1.95 




10-3 


6 


1.30 


1.18 


1.65 


1.26 


2.95 


2.44 


11-1 


6 


1.0.5 




0.85 




1.90 




11-2 


6 


0..50 




0.35 




0.85 




11-3 


6 


1.00 


0.85 


0.80 


0.67 


1.80 


1.52 


12-1 


6 


1.07 




2.05 




3.12 




12-2 


6 


1.70 




2.45 




4.15 




12-3 


6 


1.20 


1.33 


1.40 


1.96 


2.60 


3.29 


13-1 


6 


3.0.5 




3.70 




6.75 




13-2 


6 


3.10 




3.95 




7.05 




13-3 


6 


3.50 


3.22 


4.45 


4.03 


7.95 


7.25 


17-1 


6 


3.05 




4.05 




7.10 




17-2 


6 


2.25 




3.55 




5.80 




17-3 


6 


2.85 


2.72 


3.20 


3.60 


6.05 


6.32 


18-1 


6 


3.25 




3.90 




7.15 




18-2 


6 


2.05 




2.65 




4.70 




18-3 


6 


2.85 


2.42 


3.95 


3.50 


6.80 


6.22 


21-1 


6 


2.50 




3.40 




5.90 




21-2 


6 


2.65 




3.95 




6.60 




21-3 


6 


3.45 


2.87 


3.30 


3.55 


6.75 


6.42 


26-1 


6 


1.10 




0.85 




1.95 




26-2 


6 


0.95 




0.85 




1.80 




26-3 


6 


1.30 


1.12 


1.05 


0.92 


2.35 


2.04 



GENERAL DISCUSSION 

The limited time available for this study made it impossible to 
make all the determinations upon each of the several horizons of all 
the soils collected for this study. 

It was believed, however, that the additional data were not re- 
quired, since that already at hand seemed to give ample evidence upon 
which to base conclusions. Therefore, in many cases determinations 
were run on the surface horizon only. This makes some of the tables 
appear incomplete. 



468 University of California Publirations in Agricultural Sciences [Vol. 3 

On the basis of the preceding results and discussions some general 
treatment is possible, as well as a more or less critical discussion of the 
methods of soil surveying pursued by the Bureau of Soils. 

The types and the localities of collection of the soils studied were 
as follows: 

Diablo clay adobe: Thalheim (17) 

San Juan Capistrano (1) Madera (18) 

Los Angeles (2) Merced (21) 

Calabasas (5) Del Mar (26) 
Danville (6) Hanford fine sandy loam: 

Altamont clay loam Elk Grove (14) 

Walnut (3) Acampo (15) 

San Fernando Valley (4) Woodbridge (16) 

Mission San Jose (7) Waterford (19) 

San Joaquin sandy loam: Snelling (20) 

North Sacramento (10) Basset (22) 

Lincoln (11) Anaheim (23) 

Wheatland (12) Los Angeles (24) 

Elk Grove (13) Van Nuys (25) 

Note. — Figures following localities design.ite sample numbers. 

Comparisons of Physical Data 

The mechanical analyses of the soils were carried out with both 
the Hilgard elutriator and the Bureau of Soils centrifuge methods. 
The tedious nature of tlie elutriator method has been emphasized else- 
where. The results by this method show that the soils of each type 
as a whole are somewhat similar, though no two are identical and 
some samples of a type are widely divergent from the rest. The 
Bureau of Soils method appears to give a sharper and more satisfac- 
tory separation into classes than does the elutriator method. This is 
to be expected since the separates represent greater ranges of particle 
sizes. As a check on the texture of the samples collected, it shows that 
some of the soils are not true to name, therefore that all soils mapped 
under a given type name are not closely similar to one another. Of 
course, this is the belief of many soil surveyors, but it seems strange 
that in the present work, where there was the attempt to select soils 
representative of the class and type chosen for study, that such diver- 
gences developed. It is an interesting commentary on the personal 
equation of the field worker, in this case of the writer, who collected 
the samples. 



1919 J Pendleton: A Study of Soil Types 469 

With regard to the methods of mechanical analysis, one should not 
overlook Mohr's work on The Mechanical Analysis of Soils of Java,^" 
which gives an excellent discussion of the relative merits of the better 
known systems of mechanical analysis. He describes a modified cen- 
trifuge method preferred by him. 

Under a discussion of the physical constants of soils, Free^^ dis- 
cusses the value of mechanical analysis as a soil constant, and shows 
that there are three serious errors in the determination, all of which 
impress themselves upon one making and using such analj'ses. They 
are: "(1) disunity of expression; (2) failure to express conditions 
within the limits of individual groups; and (3) failure to take 
account of variations in the shapes of the particles." Yet he emplia- 
sizes, and rightly so, "that mechanical analysis is by no means useless 
nor to be belittled as a means of soil investigation. ' '^^ 

MoisUtrr equivalents. — This determination showed quite distinct 
averages for the types, though there was considerable variation within 
each of the types. Eliminating those samples shown to be non-typical 
according to the mechanical analj'sis, the variation within the type is 
reduced considerably. Yet it cannot be said that as regards this con- 
stant that all soils mapped under a given type name, or even those 
soils under a given type name which the mechanical analj'sis has 
shown to be true to name, have closely similar moisture equivalents. 
Briggs and McLane^'' express the belief that ultimately moisture ' 
equivalent determinations will replace mechanical analysis in the 
classification of soils, because the determination is simple and the 
result can be expressed as a single constant. 

Hygroscopic coefficient. — The two heavy types show averages dis- 
tinct from those of the two light types, but the wide and erratic varia- 
tion within the type, together with the nearly universal failure of 
Briggs and Shantz's formula^* to convert these values into values 
even approximating those of the m^oisture equivalent, leads one to 
doubt the accuracy of these figures of the hygroscopic coefficient. It 
is because of the ease of determining the moisture equivalent, and 
because of the difficulties involved in correctly carrying out the hygro- 
scopic coefficient, that the doubt is cast upon the latter determination. 



3» Bull. Dept. of Agr., Iiides Neerland, 1910, no. 41, pp. 33. 
31 Free, E. E., Studies in Soil Physics, Plant Worlil, vol. 14 (1912), nos. 
3, 5, 7, 8. 

^2 Ibid., p. 29. 

33 Proc. Amer. Soc. Agron., vol. 2 (1910), pp. 138-47. 

34 U. S. Bur. PI. Ind., Bull. 230 (1912), p. 72. 



470 University of California Publications in Agricultural Sciences [Vol. 3 

Comparison of Chemical Data 

The total nitrogen content of the samples of each type varies 
within somewhat wide limits. The average amounts for the several 
types are distinct, thougli the variations are such that some of the 
quantities of one type overlap those of another type. It is believed 
that for the types selected the field differentiations do indicate dif- 
ferences. 

Regarding the humus content of the four types under considera- 
tion, the results are somewhat dift'erent. The average amounts of 
humus are almost alike in three of the four types, while the nitrogen- 
poor San Joaquin soil has an average of about half that of the others. 
Within the type the soils may be very nearly alike in the humus con- 
tent, as is the case in two of the types, or maj^ be widely variable, as 
in the Hanford fine sandy loam. It should be noted that the amount 
of humus as shown by the method used, is not indicated by the inten- 
sity of the color either of the soil or of the resulting extract. This 
confirms the findings of Gortner, whicli are cited elsewhere. 

There was quite a wide range shown in the results of the deter- 
mination of the loss on ignition. The Diablo and Altamont soils, be- 
cause of the heavier textures and the relatively large amounts of com- 
bined water, and of considerable amounts of CaCO, in at least one 
case, gave high losses on ignition. The averages were close, 6.8% for 
the Diablo, and 6.7% for the Altamont. The Hanford soils were 
lower, though with a wider range. Soil no. 14, with 6.9% loss on igni- 
tion, sliows almost double that of any other soil in the type. The San 
Joaquin soils, with an average of 2.6%, show the lowest average loss 
on ignition. The smaller amounts of organic matter in these soils is 
one reason for the smaller loss. The two heavier types have averages 
close together, and the lighter types have averages not far apart, but 
because of the wide variations within each type, the results of the 
determination of the loss on ignition certainly do not show that all 
soils classified in one type are closely similar. 

Hall and Russell, in their discussion of the soils of southeastern 

T^ , -. ,. • ■. n , , . J, % total nitrogen , , , 

England,^" con.sider ot value the ratio ot rr-j ; — ^- — out apply- 

% loss on Ignition, 

ing this ratio to the California soils under consideration does not seem 

to give any relations of value. The Diablo ratio varies from 0.0136 to 

0.0158, the Altamont from 0.0141 to 0.0204, the San Joaquin from 

0.0144 to 0.0232, and the Hanford from 0.011 to 0.0172. 



35 Jour. Agr. Sci., vol. 4 (1911), pp. 182-223. 



1919] Pendleton: A Study of Soil Types 471 

The calcium (as CaO) content of the soils is interesting especially 
because of the variability. The Altamont samples show the greatest 
variation, for the largest quantity of CaO is about seven times the 
smallest. The San Joaquin samples are second, with the largest over 
six times the smallest. The Diablo samples are third, with the largest 
over five times the smallest, while the Hanford soils show the least 
variation, the largest being less than twice the smallest. There are 
quite marked differences between the averages of the Diablo, Alta- 
mont, and Hanford soils (the San Joaquin samples are intermediate), 
but the wide variations within the types greatly minimize any sig- 
nificance the averages might have. Hence it is not possible to state 
that one or another type, as represented by these samples, is charac- 
terized by high, low, or moderate amounts of calcium. 

As the analyses of the samples for calcium failed to point out any 
striking characteristics, unless it be that of variability, so it is with 
magnesium. Magnesium (as MgO) is variable within each of the four 
types. The largest quantitj' is about three times the smallest in the 
Diablo, San Joaquin, and Hanford types, while in the Altamont the 
largest is twenty-seven times the smallest. Considering the Hanford 
and San Joaquin, or the Diablo and San Joaquin, it is seen that the 
curves do not overlap, while the Diablo and Altamont, or the Diablo 
and Hanford curves do. The averages of the four types are distinct, 
except between the Hanford and Diablo, which are quite close. But, 
here again, because of the more or less wide range of values within 
each of the types, the averages are of little significance. The lime- 
magnesia ratio is very variable in these soils. Comparing the calcium 
and magnesium curves for the several soils gives a good idea of the 
relations. The Diablo curves are quite similar except for soil no. 6, 
which shows 3% MgO and 0.5% CaO. In the Altamont soils the 
curves are somewhat similar in direction, though the ratios differ 
widely. In the Hanford and San Joaquin types the ratios of CaO and 
MgO are also far from constant, yet it is readily seen from the graphs 
that the amount of magnesium varies more or less directly with the 
amount of calcium. 

Respecting the total phosphoi-us (as PoOj), if the San Joaquin and 
Hanford samples alone be considered, there would be no doubt as to 
the significance of the field separation, the variations within the type 
notwithstanding. But when the other two types are considered, the 
ease is not so good in favor of the field classification. The Diablo soils 
show considerable variation in the amount of P.^Oj, while the three 



472 University of California Puilications in Agricultural Sciences [Vol. 3 

Altamont samples show much variation. Therefore with reference to 
the amount of i^hosphorus, and the types studied, the separation into 
types may or may not be of significance. 

If tlie results of the potassium (K„0) determinations are com- 
pared, it is very evident that but one conclusion can be drawn, and 
that is that the variations in the amount of potassium within each 
type are great enough so that any differences between the averages 
of the several types have no significance whatsoever. Therefore, with 
regard to total potassium the field separation of soils as represented 
by these twenty-four samples of four types means nothing. 

Comparison of Bactebiological Data 

The wealth of the data obtained from over nine hundred bacteri- 
ological tumbler cultures is hardly of sufficient significance to com- 
pensate for the effort involved. There is one outstanding conclusion 
from all this work, namely, the lack of any very definite, distinct, and 
constant bacteriological activity of the samples of one type that is not 
to a con.siderable extent shared by the samples of the other types. 
There are tendencies in certain types with regard to bacteriological 
activity which show that some of the types as a whole are more or less 
distinct from one or more of the others. 

Ammonification. — The amount of ammonia produced from dried 
blood varies to a great extent. The Altamont samples gave between 
10 and 33 mg. nitrogen as ammonia ; the Diablo samples gave between 
7 and 26 mg., and the Hanford samples gave between 35 and 72 mg. 
The Altamont and Diablo types are thus seen to be about alike in their 
low ammonifying power, as compared with the higher ability of the 
San Joaquin types and still greater ability of the Hanford types. 
And since there are somewhat greater variations between the tj'pes 
than between the samples of a given type, the ammonifying power 
may be significant. 

Nitrogen fix,ation. — The two heavy types, Diablo clay adobe and 
Altamont clay loam, show no characteristic differences, while the two 
lighter types show considerable differences. As a whole the types are 
different one from another, yet the variations within the type are 
sufficient to prevent any statement that the rate of nitrogen fixation 
is a function of the type as determined in the field, or vice versa. 

Nitrification. — The nitrification data are the most puzzling. The 
figures are extremely variable within a given type ; the erratic way 



1919] Pendleton : A Studtj of Soil Types 473 

ill which the Haiiford samph-s behave is not paralleled by any other 
type. There are certain ways in which the types are distinct : 

The nitrification of the soil's own nitrogen as compared with tlie 
soil's action upon added nitrogen is in some degree separate for each 
type. The San Joaquin samples nitrified their own nitrogen to a 
greater degree than they did the nitrogen added to the soil. 

The relative nitrification of the several nitrogenous materials 
(dried blood, cottonseed meal, ammonium sulfate) is in some measure 
distinct for the several types. The Diablo, Altamont, and San Joaquin 
types show ammonium sulphate to be nitrified the best, cottonseed meal 
less, and dried blood still less. The Hanford samples show cottonseed 
meal to give the highest percentage of nitrates, with dried blood less, 
and ammonium sulfate still less. 

When any one soil is compared through the three sets of deter- 
minations there are no apparent similarities. The Hanford type 
shows the greatest bacterial activity, while the San Joaquin shows 
less, with the heavier types showing sometimes greater activity and 
sometimes less than that of the San Joaquin. 

Work in Other States 

In connection with the original chemical work reported in this 
paper, tliere should be mentioned the large amount of work done in a 
number of states on the analysis of the types of soils as mapped by 
the Bureau of Soils. Apparentlj^ these analyses have been made 
without any question as to the validity of the existing subdivisions 
into types. The various analyses have been reported with some com- 
ment, but that which does appear usually deals with the "adequacy" 
or "inadequacy" of the plant food present. Blair and Jennings'" 
present a large amount of data on chemical composition, some of 
which on rearrangement show interesting relationships (table 85). 
From the data the four series of soils with the largest number of 
analyses were selected (see following table). Under each series there 
are from 2 to 4 soil types, and from 2 to 6 analyses under each type. 
The averages from each type are tabulated, also the averages of all 
the types within the series. This is both for the strong acid extraction 
and the fusion methods of analysis for significant plant food elements. 
There are no doubts but that each series of soils shows characteristic 
chemical peculiarities, peculiarities which are to a great extent con- 



38 The Mechanical and Chemical Composition of the Soils of the Sussex Area, 
New Jersey, Geol. Surv. N. J., Bull. 10, 1910. 



University of California PuhUcations in Agricultural Sciences [Vol. 3 






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1919] . Peiidlelon: il Study of Soil Types 475 

stant throughout the several representatives of the type. lu some 
eases, the differences or similarities ai'e more clearly seen in the total 
analyses, and in other eases, they appear in the acid analyses and not 
in the fusion analj-ses. "Within any series the variations between 
analyses of any one type are about the same as the variations from 
type to type. There are many other papers" which provide material 
for similar comparisons. 

A paper by Van Dyne and Ashtou'* reports chemical analyses for 
lime, phosphoric acid, potash, and nitrogen on the samples collected 
in the course of the survey of Stevens County, "Washington. Though 
sometimes there is a much greater range within a type than between 
types, in a general way the analyses for any one type agree quite 
well. As a whole the chemical analyses seem to show that the field 
criteria are also a basis for grouping soils into certain chemical 
groups. It should be mentioned that the work of Blair and Jennings, 
also that of Van Dyne and Ashton, deals with individual areas, and 
not with samples from several scattered areas. The work of Fraps and 
"Williams, and the original work here reported represent scattered 
areas. 



The Greenhouse Cultures 

By far the most interesting results were obtained in the pot culture 
work. It is realized that there are vai-iations in the phjsical nature 
of the samples of a given type, yet since these samples were collected 
with considerable care by one familiar with field classifications, the 
samples so selected should be fairly representative of the type. It is 
probable that if all the soils in each of the types used were exactly the 
same in texture, i.e., if the mechanical analysis showed the same 
results for the several soils, the crops produced on the several soils of 
a type would be less divergent in appearance or weight. Yet it is 
not at all likely that the crops would be the same. Pot cultures pre- 
sume that the conditions in all the pots can be kept uniform, but this 
is obviously impossible. Greenhouse work is subject to many interfer- 
ing factors. Nevertheless, the results are believed to be significant. 



3T Williams, and others, Eeport on the Piedmont Soils, North Carolina Dept. 
Agr., Bull. 206, 1915. 

Fraps, G. S., Composition of the Soils of South Texas, Texas Agr. Exp. Sta., 
Bull. 161, 1913; Composition of the Soils of the Texas Panhandle, ibid., Bull. 
173, 191.5. 

3S Van Dyne and Ashton, Soil Survey of Stevens County, Washington, Field 
Operations, V. S. Bur. Soils, 1913, pp. 2165-2295. 



476 University of California Publications in Agricultural Sciences [Vol. 3 

despite the large correction that the consideration of the probable 
error might introduce. 

The differences in the crop producing power of the soils are verj^ 
marked in the Diablo clay adobe, where the second crop, as well as 
the first, shows evident variations in the ability to support a crop. 
In the Altaraont clay loam the second crop almost loses the variations 
seen in the first crop from pot to pot. The samples of both types 
seem to show one thing in common — the approach of the several sam- 
ples toward a uniform ability to produce crops, as the soils are kept 
for longer periods under the same conditioiis. The Hanford soils did 
not show, with the several crops, the parallelism in the fertility from 
crop to ci'op as did the Diablo and Altamont soils. Some soils pro- 
duced good crops of grain and poorer crops of legumes, others did the 
opposite. The low nitrogen content in this type seemed to be a limit- 
ing factor. This would account for the variation between the grain 
and the leguminous crops. Also, the presence, or absence of Bacillus 
radicuola inoculation in this connection might greatly affect the total 
crop produced. 

There does not seem to be much doubt but that the soils of the 
several types compared in this way are not the same, though they are 
in certain respects similar. 

The Place of Soil Classification. — With all these evidences that the 
soils within the several types are not closely similar, though they are 
classified the same by the B^^reau of Soils, what conclusion is one to 
reach as to the value of such a classification? If it were true that there 
were no appeal from the findings of such laboratory and greenhouse 
determinations as these, and that these determinations were a final 
proof of the fertility or infertility of a soil, obviously there would be 
but one thing to do — discard all such field classifications as useless. 
But the writer is one of a great many soilists who are not willing to 
rely on laboratory or even greenhouse results for an absolute deter- 
mination of fertility, and for the grouping together of soils into a 
workable classification. Not enough is definitely known as to the mean- 
ing of such findings, tliough there are certainly many valuable points 
shown by laboratory analyses.-"' 

As examples of the value of natural classifications we may con- 
sider those of botany, zoolog.y, or mineralogy. If available, a wholly 
satisfactory classification of soils would be equally useful. The appre- 



3SI Jordan, W. H., Measurements of Soil Fertility, New York Agr. Exp. Sta., 
Geneva, Bull. 424, 1916. 



1919] Pendleton: A SUidy of Sail Types 477 

ciation of this is shown in the many systems of soil classification that 
have been proposed. 

Despite the foregoing facts that have been obtained showing the 
divergent properties of different samples of one type presumably 
alike, yet it must be admitted that soil surveys, even such as are no 
more refined than those of the Bureau of Soils, have considerable 
value for field use. 

It is felt that the additional effort required to modify the practices 
of the Bureau of Soils in the mapping and classifying of soils would 
be more than justified by tlie increased accuracy and usefulness of 
the maps. To point out some of the causes of the present practices 
and to give suggestions for possible methods of improvement, the 
following discussion of the Bureau of Soils methods has been 
prepared. 

Discussion of the Bureau of Soils' methods. — The methods of map- 
ping and classifj'ing soils, as devised and iised by the Bureau, have 
resulted from some definite and important considerations. 

1. The necessity for keeping down the cost of surveying and map- 
ping prevents the use of laboratory and culture methods in the study 
of the soils classified, even if it were not for the fact that one of the 
outstanding policies of the Bureau apparently denies the validity of 
such studies in the classification of soils. This does not include the 
mechanical analysis of soils, which is not a separate laboratory deter- 
mination, but a method of checking the field man's decision as to the 
texture. It should also be added that some of the reports as published 
in the Field Operations of the Bureau of Soils, for 1913, show the 
subdivision of the soils into two groups ba.sed upon the CaCO., content. 
Keeping down the cost has also prevented the use of sufficient time to 
map the soils correctly, even according to the criteria admittedly of 
value in the system adopted. Many of the other methods of classify- 
ing and mapping soils, even if applicable to most of the agricultural 
regions of the United States, woidd be absolutely ovit of the question 
on account of cost. 

2. The large and widely divereified area of the United States, and 
the attempt to map representative areas in various parts of the coun- 
try, early led to difficulties. There seemed to be a lack of understand- 
ing as to what criteria to use in the classification of the soils. Re- 
cently, some of the areas first mapped in the state of California have 
been resurveyed. The texture, series, and province differences of the 
early mapping seem not to have been clear. For example, we may con- 



478 University of California Fablications in Agricultural Sciences [Vol. 3 

sider the differences between the older and the recent survey of two 
localities east of Los Angeles. The notes were made by C. J. Zinn, 
a member of the party which made the recent survey: 

Locality A — About 15 square miles with Eaton Wash on the west, center of 
Monrovia on the east, mountains on the north, and a line about 3 miles south of 
mountains as the south boundary. The old surveyio lias four types of three series 
and two miscellaneous types: San Gabriel gravelly loam, San Galiriel gravelly 
sand, Placentia sandy loam, San Joaquin black adobe, and Kiverwash and Moun- 
tains. The new survey (1915, unpublished) has 13 types of 6 series and 3 mis- 
cellaneous types: Hanford stony sand, gravelly sand, loam, sandy loam, fine 
sandy loam, and sand ; Tejunga stony sand ; Zelzah loam and stony loam ; Pla- 
centia loam, Holland loam, Chino loam and sOt loam. The miscellaneous types 
are Eough Mountain land. Bough Broken land, and Kiverwash. 

Locality B — In the city of Pasadena, comprising about 3.5 square miles, with 
the southwest corner at the center of the city. The old survey*i shows San 
Gabriel loam occuping about 0.6 of the area, San Gabriel gravelly sand about 0.3, 
and Placentia sandy loam about 0.1. The new survey (1915, unpublished) shows 
Zelzah gravelly loam occupying about 0.9 of the area, Zelzah loam about 0.1, with 
a very small body of Holland loam. The older survey showed a recent alluvial 
soil where the recent one sliows an old valley filling soil. 

Besides these erroi-s (detected as sucli l)y the practical man, who 
might attempt to use the soil maps in the field) there are in addition 
those of another nature which were the source of much criticism in the 
earlier history of the survey — the so-called "procrustean classification" 
criticism of Hilgard."*- Due apparently to an insiifificient studj- of the 
soils of the United States, there was the attempt to classif j" in the same 
series soils of widelj' differing properties — diff'ex-ences of an important 
nature being ignored. 

At the present time there is an increasing tendency toward limit- 
ing series groups of soils to a more or less definite climatologieal 
region. In this connection see the later changes in the correlation of 
many soils.*^ These changes tend to limit the geographic range of the 
series, and make these series narrower and more exact. Moreover, it 
is understood that as the knowledge of the soils has increased, the 
changes in correlation have been proceeding rapidly since the above 
list was issued. This indicates that as the facts accumulate the "pro- 
crustean classification" criticism is losing its force. 



40 Field Operations of the U. S. Bur. of Soils, 1901, San Gabriel sheet. 

41 Ibid. 

■IS Hilgard, E. W., and Loughridge, R. H., Proc. Second Intern. Agrogeol. 
Conf., Stockholm, 1910, pp. 228-29; Hilgard, E. W., U. S. Office Exp. Sta., Bull. 
142 (1904), p. 119; Hilgard, E. W., Proc. First Intern. Agrogeol. Conf., Builapest, 
1909, pp. 52-54. 

43 U. S. Bur. Soils, Bull. 96, 1913. 



1919] Pendleton: A Study of Sail Types 479 

3. There was a lack of trained men early in the work. This was 
to be expected. As has been shown, the early surveys were very crude 
in certain places. It must be added that some of the errors and omis- 
sions made in the more recent maps are not due to a lack of training, 
but to the carelessness of the field men with respect to details. 

4. The policy of the Bureau has been to recognize the physical 
characteristics of the soil as factors in fertility to the virtual exclusion 
of the chemical or biological factors. Therefore the use of physical 
criteria is necessary. Besides, the criteria must be such a.s can be 
applied in the field, and are: (1) color, (2) texture, determined by 
rubbing between the thumb and finger, (3) structure, (4) nature of 
subsoil, (5) presence of hardpan, (6) height of water table, (7) pres- 
ence of alkali, (8) topography, (9) phj^siographic form and hence 
mode of formation, and (10) source of material (sedimentary, igne- 
ous, or metamorphie rocks). Ilumus, and the presence or absence of 
appreciable quantities of lime, also the reaction of the soil (acid or 
alkaline) are frequently guessed at. These criteria are practically 
the only ones that can be applied in field work. It is believed that 
these same criteria indicate the chemical nature of the soil, though 
there has been no attempt to correlate some of the factors. However, 
the original work reported in this paper would indicate that the chem- 
ical nature is not tlie same, of soils classified the same by the Bureau 
of Soils criteria. 

5. The desire to limit the number of groups of soils is a wholly 
sound one. In discussing the problems of classifying soils there 
should always be kept in mind the fact that some of the problems are 
not very different, fundamentally, from some of the problems that 
have been causing perplexity among biologists for a long while. 
The tendency, as seen in some of the recent surveys, to make the 
series more inclusive and to introduce the term, phase, is heartily 
commended. By making the series broader there will be less difficulty 
in placing a soil in its proper group. The phase will take care of many 
of the series differences between area and area. 

6. It seems certain that if there were more emphasis placed upon 
the inspection of the area, during the progress of the field work and 
after its completion, there would be a much closer approach to 
accuracy throughout the map and report. At the present time the 
field man is not closely checked up. The careless or indifferent worker 
can map more or less as he pleases, especially in the out-of-the-way 
places. 



480 University of California Pttblications in Agricultural Sciences [A'ol. 3 

7. Whether the soil survey should include more than a simple 
classification of the soils or not, is an unsettled question. It is thought 
hardly possible that in a soil survey the field man could handle all the 
phases of an agricultural survey of an area, when his energies should 
be fully employed in the classification of the soils. It is believed that 
the place of the sun'ey, in this country at least, is to handle the 
classification of the soils, leaving the study of the remaining factors 
largely to other specialists, who would use the soil survey as a basis.** 
But to make the soil maps of more general use for such work, they 
must be more accurate. These maps never can become the basis of 
other agricultural studies as long as many experiment station workers 
ridicule them. Hence, the ultimate effort of the survey should be 
toward better work, rather than covering a wide range of agricixltural 
studies. 

8. There is not the incentive to make as many separations of the 
soils in the field, as the field man might think best, because frequently 
the feeling of the editors is that there would be too many small bodies 
of soil shown on the manuscript maps which would not warrant the 
additional cost of publication. 

In conclusion, the Bureau of Soils' system has much to commend 
it as a field method, and the resulting maps and classification are be- 
lieved to be of distinct value. It is felt that a more general luider- 
standing of: (1) the limitations under which the maps, the earlier 
ones especially, have been made; (2) the difficulties under which the 
field work is at present carried on; (3) the meaning of the correlation 
of soils; and (4) the general policy of the Bureau of Soils would give 
people more .sympathy with their work. 



■nFippin, E. O., Proc. Amer. Soc. Agron., vol. 1 (1908), pp. 191-97. 



191P] Pendleton: A Stndy of Soil Types 



SUMMARY 



Presumably typical samples of four soil types were collected for 
laboratory and greenhouse study from widely distributed localities in 
the state of California. The field appearance of each sample was 
usually sufficient to warrant the classification as it exists. 

Physical Relations 

1. The mechanical analysis bj- the Hilgard elutriator shows that 
the soils of a given type are in some cases quite divergent from each 
other iu their content of certain of the sizes of particles. The mechan- 
ical analysis by the Bureau of Soils method shows that 6 of the 24 
soils were not true to their type names, and that of those soils within 
the type there is considerable variation. 

2. The moisture equivalents for the several types show distinct 
enough values to sulistautiate the field separation. 

3. The hygroscopic coefficients varj' widely within each type and 
the types are not .shown to be distinctly different by this criterion. 

Chemical Relations 

1. The total nitrogen averages vary markedly from type to type, 
with the Altamont clay loam containing three times that in the San 
Joaquin sandy loam. 

2. The average humus content of the San Joaquin samples is 
about half that of the other types. The variations in the humus con- 
tent between the types are small, considering the diverse nature of the 
types and the large range in the amount of humus within the type. 

3. The loss on ignition shows a considerable variation within the 
type and no significant distinction between the four types. 

4. The average total calcium content of tlie types is distinct, 
though the wide range within each type minimizes the significance of 
the variation in the averages. 

5. With regard to magnesium, the tA'pes are neither distinct nor 
are the soils within the type closely similar, 

6. The average phosphorus content of the types is distinct, though 
the ranges within the several tj'pes frequently overlap. 

7. The total potassium results do not show the types to be distinct 
nor the soils within a type closely similar. 



Vniversity of California Publications in Agricultural Sciences [Vol. 3 



Bacteriological Relations 

1. The ammonifying power shows rather larger variations from 
type to type than between the samples of a type. 

2. The nitrogen fixation data do not show characteristic differences 
for the several types. 

3. Regarding nitrification as a whole there may be a greater 
divergence between the samples of a type than between types. The 
relative nitrification of the soil's own nitrogen varies with the type, 
as does the relative nitrification of the several nitrogenous materials 
added. 

Pot Cultures in the Greenhouse 

In addition to the effect of tlie probable error, the impossibility 
under the conditions herein described of growing the same crops on 
all the soils, during the same season of the year in the greenhouse, 
prevents close comparisons between the types, or between the first and 
second crops on a given soil. The comparison of several samples of a 
given soil type and the comparisons of various soil types, according 
to the previously outlined greenhouse methods show that : 

1. Different representatives of a given type are not the same in 
their abilitj' to produce crops. 

2. The arrangement of the samples of a given type according to 
their fertility may or may not vary with the special crops used as the 
indicators. 

3. The types are distinct with respect to their fertility, considering 
their average production. 

Therefore it is concluded that with regard to the 24 soils of 4 
types examined, all soils mapped under a given name by the Bureau 
of Soils method may or may not be closely similar, depending upon 
the criteria used. The greater number of the criteria show the soils 
of a type to be not closely similar, and the types to be but litle differ- 
entiated from each other. 

In connection with the results of the author's study of the soils, 
there is given an historical sketch of the development of soil classifica- 
tion and mapping, also a discussion of certain of the methods em- 
ployed by the Bureau of Soils of the United States Department of 
Agriculture. It is pointed out that despite its defects, the work of 
the Bureau of Soils is of value, and is practically the only type of soil 
classification and mapping possible under the conditions imposed. 



1919] Pendleton: A Study of Soil Types 



APPENDIX A 
METHODS AND TECHNIQUE 

Collection op Samples 

There was difficulty in fiuding types that -would meet the requiremeuts of wide 
distribution and of differing from one another as to series as well as texture. The 
types chosen were : 

Diablo clay adobe, a residual soil. 

Altamont clay loam, a residual soil. 

San Joaquin sandy loam, an "old valley filling" (old alluvial soil). 

Hanford fine sandy loam, a recent alluvial soil. 

The first task was the collection of the samples of soil for study in the labora- 
tory and in the greenhouse. Of course, there were kept in mind the errors and 
difficulties involved in the collection of representative samples. The selection of 
the localities in which to collect samples was frequently made in consultation with 
the persons who had originally mapped the areas under the Bureau of Soils. 
This was done so that the soil chosen might as nearly as possible represent what 
the surveyor had in mind as characteristic of the type within the area. It was to 
be expected that the ideal type which one man would use as a guide as he did the 
mapping in one area would not always be identical with that which another man 
might use in mapping another area, despite the aid of the inspector in keeping the 
ideal types of the field men as nearly alike as possible. Some of the accompanying 
index maps, showing the places where the soil samples were collected, are dupli- 
cates of the same locality. As the dates show, one is a portion of a less recent, 
and the other of a more recent survey. In many cases the index maps have been 
copied from the manuscript maps, a number of surveys in this state not yet being 
published. For a discussion of the differences in these maps, see below the section 
on The Criticism of the U. S. Bureau of Soils Method of Surveying. 

Not only were the field men questioned about the locality, but as nearly as 
possible an exact designation was obtained on the soil map itself. In the collec- 
tion of some of the samples the writer had the good fortune to have the assistance 
of the man or men who actually mapped the soils in question. Sometimes there 
was no trouble at all in locating a typical body of the soil where a sample might 
be taken. On the other hand, as in the case of the collection of the Hanford fine 
sandy loam from Woodbridge (nos. 15 and 16), more than two hours were speut 
in driving about, trying to find a place that seemed a typical fine sandy loam. 
Experience shows that the personal equation in field work is very important and 
is hard to controL^s 

No special attempt w'as made to obtain virgin soil, for the types of soils that 
had been selected for study were mainly agricultural, and most of the soils have 
been at some time under cultivation, if they are not now. Also, there has been 
little, if any modification of the agi-icultural soils by the addition of fertilizers. 
Hence the small tracts of the Hanford fine sandy loam, for instance, that are still 
virgin are largely non-agricultural, waste land areas, and would not illustrate the 
properties of the type as a whole. Not so large a part of the San Joaquin sandy 
loam is under cultivation now, though almost all of it has been farmed to grain 
in the past. The two minor types studied, the Altamont clay loam and the Diablo 
clay adobe, being of residual origin and occupying rolling to hilly or mountainous 
land are also not very extensively farmed. The topography is the limiting factor 
in most cases. 



^i' Fippin, E. 0.. Practical Classification of Soils, Proc. Amer. Soc. Agron., vol. 3 (1911), 
pp. 76-89 ; Increasing the Practical Efficiency of Soil Surveys, Proc. Amer. Soc. Agron., 
vol. 1 (1907-1909), pp. 204-06. 



484 University of California Fnblications in Agricultural Sciences [Vol. 3 

The ideal way to collect a representative sample of soil for laboratory studies 
is to make a number of borings scattered about the field or fields, so that the sam- 
ple will approximate an average. But in the case of collecting the samples for this 
study it was considered best not to attempt such a procedure, for the reason that 
it was desired to have the samples for the greenhouse work and for t'le physical, 
chemical, and bacteriological studies, come from the same lot of soil. The collec- 
tion of such a large amount of soil, about 2.50 pounds in all, from a number of 
places about the selected field would be very tedious. Hence as nearly a typical 
place as possible was selected, close to a wagon road, in order that the samples 
could be transported readily. Care was used that the location be far enough out 
into the field to allow the sample to be representative of the conditions in the field. 

The subsequent procedure w'as as follows: The selected spot was cleared of 
grass or other surface material or accumulation that did not belong to the soil. 
A hole was dug, usually one foot deep (the depth depending entirely upon the 
nature of the surface soil and any noticeable changes toward the subsoil), and 
big enough to give sufficient soil to make up the greenhouse sample of from 225 
to 250 pounds. The soil was shoveled directly into tight sugar or grain sacks, no 
attempt being made to mix the sample at this time. Some sacks of the soil would 
contain more of the surface material, and others more of the lower portion, but a 
later thorough mixing and screening at tlie greenhouse gave a uniform sample. 
After the large sample was collected, the hole was usually dug two feet deeper, 
giving a hole three feet deep. One side of this hole was made perpendicular, and 
from this side the small samples were collected. The A, B, and C horizons were 
marked off on this wall, and the samples collected by digging down a uniform 
section of the designated portion, using a geologic pick and catching the loosened 
material on a shovel. About ten pounds of soil were so collected, and placed in 
clean, sterile canvas sample sacks. Care was used not to contaminate the samples, 
so that the bacterial flora might remain nearly unaltered. It seemed imprac- 
ticable to attempt to collect the laboratory sample under absolute sterile condi- 
tions, especially since some of the deeper (B and C) samples were obtained by 
means of the soil auger. When the auger was used to collect the samples from 
greater depths the boring was done from the bottom of the hole made in collect- 
ing the larger sample. The size of the laboratory sample required the boring of 
five or six holes with the usual 1.5 inch soil auger. The laboratory sample of the 
first foot, or the A sample, was always collected from the side of the large hole. 
Notes regarding the sample, field condition, the place of collection, together with 
photographs and marked maps are given in appendix B. 

As described above, the soils were collected in separate portions from the sur- 
face to the 12 inch, from the 12 to 24 inch depth, and from the 24 to 36 inch 
depths where there were no abrupt or marked changes in the color, texture, or the 
like, as in the Hanford fine sandy loam. But since in some cases, as most fre- 
quently in the San Joaquin sandy loam, the samples do not represent the first, 
second, or third foot depths, as the case might be, the term, horizon, has been 
used. Horizon A indicates the surface sample, horizon B the second sample, and 
horizon C the third sample. 

Laboratory Preparation of Samples 

The large samples were stored in the greenhouse untU ready for use. The lab- 
oratory samples were allowed to remain in the sacks until air dry, when they were 
passed through a 2 mm. screen. This was a difficult matter, with the heavy soils, 
as well as with the heavy subsoils of the San Joaquin sandy loam. Cautious use 



1919J Pendleton: A Study of Soil Types 485 

of the iron mortar was necessary to supplement the rubber pestle." The samples 
were thoroughly mixed after screening, when they were weighed and placed in 
sterile containers — glass jars and large bottles. Precautions were taken as far 
as possible to avoid contamination of the samples during this preparatory process. 
The screens, mortars, scoop, and pans were flamed out between samples. Obvi- 
ously contamination could not be avoided absolutely without too great a prolonga- 
tion of the work. 

The material not passing the 2 mm. screen was subsequently washed on the 
screen, with a stream of water to remove the finer material. The residue not 
passing the screen by this treatment was dried and weighed. It seemed unneces- 
sary to adopt elaborate precautions, like those described b_v Mohr," to obtain the 
exact quantities. 

Mech.vnical Analysis 

The Hilgard elutriator was used for the purjjose of making the mechanical 
analysis of the samples (surface horizon only). For the purpose of this work 
the method described by Hilgard" has been modified in several respects. The pre- 
liminary preparation by sifting through the 2 mm. sieve in the dry state, and 
through the 0.5 mm. sieve by the aid of water was used. One hundred grams was 
sifted with the 0.5 mm. sieve, and the fine material plus the water was evaporated 
to dryness on the water bath. The dry material was broken up and from this 
the samples were weighed out for the analysis. 

The samples were not disintegrated by boiling, since it was believed that such 
treatment would affect the "colloid" content of the sample. Instead, the samples 
were shaken with water in sterilizer bottles for three hours, similar to the treat- 
ment preparatory to the mechanical analysis by the Bureau of Soils method. 
However, not boiling the samples caused more work later. 

The colloidal clay was removed by placing the previously shaken sample in a 
large precipitating jar and stirring up mth several liters of distilled water. (Dis- 
tilled water was used throughout the analysis.) The quantity of water was not 
important, but rather the depth of the suspension, which was 200 mm. After 
allowing to stand for 24 hours the supernatant turbid water was siphoned off, 
when the residue in the bottom of the jar was again stirred up with water and 
the clay again allowed to settle out of a 200 mm. column. This was repeated 
until the supernatant liquid contained practically no material in suspension after 
standing for 24 hours. The clay suspensions were placed in large enamelware 
preserving kettles, and the solutions reduced in volume by boiling. The final 
evaporations were carried on over the water bath, so as to avoid too high a tem- 
perature. 

A large portion of the finest sediment (0.25 nun. hydi'aulic value) was removed 
as follows: After the greatest portion of the clay had been removed by the 24 
hour sedimentation and decantation, the sample was placed in a 1 liter beaker and 
stirred up with sufficient water to make a 100 mm. column. After standing 6 
to 8 minutes the suspended material was decanted off. This was repeated until 
the supernatant solution was practically clear. The entire time for these decanta- 
tions usually occupied 2.5 or 3 hours. The decanted material was allowed to stand 
for 24 hours, as before, and the 200 mm. column decanted as with the original 
clay suspension. This was continued until the clay was practically all removed. 



"Hilgard, Calif. Agri. Exp. Sta.. Circ. 6, June, 1903. 
"Bull. Dept. Agr. Indes Neerland.. no. 41, 1910. 

'"Calif. Agr. Exp. Sta.. Circ. 6 (1903), pp. 6-15; see also Wiley, Agricultural Analysi 
vol. 1 (1906), pp. 246-62. 



486 University of California Publications in Ai/ricultural Sciences [Vol. 3 

The residue constituted the main portion of the 0.25 mm. hydraulic value sep- 
arate. The residue from the 6 to 8 minute decantation was placed in the elutri- 
ator, and separated by the usual method into the various sizes. Since, however, 
the sample was not prepared by boiling previous to the separation of the clay, the 
clay was never as thoroughly removed from the coarser particles and the finer 
aggregate particles were not completely broken down. Hence when tlie sample 
was placed in the elutriator and subjected to the violent agitation of the stirrer 
an appreciable amount of clay passed off with the finest separate. Therefore, 
instead of allowing the water to return to the carboy from the settling bottle, 
during the running off of the finest separate, the following procedure was em- 
ployed: The water was run into precipitating jars and allowed to stand for 24 
hours, and the clay water was then decanted off and boiled down with the other 
clay water. 

A further modification of the Hilgard method was found advisable after the 
change from the large elutriator tube to the small one, preparatory to running off 
the coarser separates. The mechanical defects in the elutriator always allowed 
for the collection of a portion of the sample in crevices where the stream of water 
could not reach to carry off the particles. Hence, when the large tube was 
removed, and cleaned, there was found an appreciable amount of the finer sedi- 
ments that had not passed over. These were all added to the small tube of the 
elutriator, and the additional material of the smaller sizes run off, using an hour 
or so for each size. This seemed a better method than the separation of such 
sediments by the beaker method, as was done by Dr. Loughridge. 

The separates, after decanting most of the water, were drieil first on the water 
bath and later in the drying oven at 100°C-110°C and weighed. All of the deter- 
minations were made on the water free basis.*" 



Additional Physical Determinations 

Upon the surface or A horizon samples of the 24 soils considered in this study 
additional physical determinations were made by the Division of Soil Technology, 
through the courtesy of Professor Charles F. Shaw. These determinations were 
of the mechanical analysis by the Bureau of Soils method,''" of the moisture equiva- 
lent by the Briggs and McLanc method,*' and of the hygroscopic coefficient accord- 
int; to Hilgard 's method.'''^ 



Chemical Methods 

At first the chemical work was based upon the "strong acid extraction'-' 
method, so well known through the work of Dr. Hilgard.''' There are some very 
pertinent objections, as well as advantages, to the method of acid extraction for 
the purpose of comparing soils among themselves.'" 

Tn the analysis 2. .5 gram samples, air dry, were used throughout. The acid 
extraction results are not included in tliis paper. 

*^ The writer wishes to emphasize the tedium of the elutriator process, and to advise 
strongly against the use of the apparatus for the comparison of the soils as to texture. The 
elutriator is e.xcellent from a theoretical point of view, but the results do not at all warrant 
the extravagant use of time in the laboratory that the apparatus requires. 

»»U. S. Bur. Soils, Bull. 84, 1912. 

'^Ibid., Bull. 45, 1907; Proc. Amer. Soc. Agron., vol. 2 (1910), pp. 138-47. 

"2 Calif. Agr. Exp. Sta., Cire. 6 (1903), p. 17; Soils, pp. 197-99. 

°= Calif. Agr. Exp. Sta., Circ. 6 (1903), pp. 16ff; Soils, pp. 340ff. 

°* See Hissink, Intern. Mitt, fiir Bodenkunde, vol. 5 (1915), no. 1. 



1919] Pendleton: A Sttidy of Soil Types 487 

The sodium peroxide fusion method'" was carried out on the two larger series 
of soils, the Hanford and the San Joaquin. The elements sought were phosphorus, 
calcium, and magnesium. Five gram samples, air dry, were used throughout. 
The general method of analysis, as set forth by Hopkins, was employed, tliough 
there were a number of refinements used to increase the accuracy of the results. 
As such might be mentioned the double precipitation of the iron, aluminum, and 
phosphorus. 

Phosphorus was determined volunietrically, according to the method of Hib- 
bard.™ 

Total nitrogen was determined by the modified Gunning-Kjeldahl method, 
using ten gram samples. 

Loss on ignition was determined upon the 10 gram, air dry samples that were 
used for the determination of the hygroscopic moisture of the samples used in 
the chemical analysis. The soils were ignited in a muffle furnace to constant 
weight. 

Humus was determined by the Grandeau-Hilgard method," using 10 gram 
samples, air dry. 

Potassium was determined by the J. Lawrence Smith method, using one gram 
samples. 

Bactekiological Methods 

The only bacteriological methods employed were the determination by the tum- 
bler or beaker method of the ammonifying, the nitrifying, and the nitrogen fixing 
powers of the soils.™ All cultures were run in duplicate. 

Ammonification tests were made using 50 grams of soil and 2 grams (4%) of 
dried blood. The checks were distilled at once, and the cultures kept in the incu- 
bator at 24°C-30°C for one week. (The incubator thermostat was unsatisfactory 
in its action, hence the variation in the temperature.) 

The nitrifying power of the soil was tested as regards the soil's own nitrogen, 
dried blood, cottonseed meal, and ammonium sulfate. In the Diablo clay adobe 
and the Altamont clay loam .50 grams of soil were used, to which was added 1 
gram (2%) of dried blood, or of cottonseed meal, or 0.1 gram (0.2%) of am- 
monium sulfate. In the case of the San Joaquin sandy loam 50 grams of soil were 
used, together with 1 gram (2%) of dried blood or of cottonseed meal, or 0.2 gram 
(0.4%) of ammonium sulfate. In the series run on the Hanford fine sandy loam 
100 grams of soil were used, to which were added 1 gram (1%) of dried blood or 
of cottonseed meal or 0.2 gram (0.2%) of ammonium sulfate. It is to be regret- 
ted that the several series could not all be run on exactly the same basis as the 
Hanford series. But the small amount of stock soils of the samples of the earlier 
series precluded the use of larger original samples, not to speak of the impossi- 
bility of repeating these series. The cultures were incubated for four weeks at 
24°C-30°C. At the end of this period the cultures were dried in the oven at about 
90°C and the nitrate content determined by the phenoldisulfonie acid method 
according to the modifications of Lipman and Sharp.^' 

Nitrogen fixation. For this determination uniform quantities of soil were 
used throughout — 50 grams, to which was added 1 gram of mannite. These cul- 



'■" Hopkins. Soil Fertility and Permanent Agriculture, pp. 630-33 ; Hopkii 
Soil Fertility Laboratory Manual (Boston. Ginn, 1910), pp. 42-45. 

=1Jour. Ind. Eng. Chem., vol. 5, pp. 99S-1009. 

"Calif. Agr. Exp. Sta., Circ. 6 (1903), p. 21. 

^ Burgess. P. S., Soil Bacteriology Laboratory Manual, Easton, Pa., The i 
listing Co., 1914. 

""Univ. Calif. Publ. Agr. Sci., vol. 1 (1912), pp. 21-37. 



488 Univcrsitij nf California Publications in Affricultural Sciences [Vol. 3 

tures were iueubated for four weeks at 24°C-30°C, at the end of which time bac- 
terial action was stopped by drying in the oven for 24 hours. Subsequently, the 
samples were broken up in a mortar, and 10 grams weighed out for the determina- 
tion of the total nitrogen. 



Pot Cultures in the Greenhouse 

Tlie large samples of t!ie surface foot of soil were stored in the greenhouse 
until used. The preparation of the samples was in most cases as follows : The 
sample was placed on a large table and screened through a quarter inch sieve. 
This treatment of screening was attempted with the Diablo clay adobe and the 
Altamont clay loam, but was abandoned as practically hopeless. The samples of 
tliese two types had been collected in the late summer, when the ground was very 
hard and dry, hence the clods defied any efforts to break them up. As an alterna- 
tive the samples were as thoroughly mixed as possible and weiglied out into the 
pots. Several waterings during a week, together witli carefully breaking up the 
lumps by hand, rendered the soils finely divided enough to permit the planting of 
the seeds. The Hanford and San Joaquin types were readily screened. 

All the soils were weighed out into nine inch flower pots. In most cases the 
pots had been previously paraffined. Care was taken to clean the pots thor- 
oughly, as far as surface material was concerned; many of the pots were scrubbed 
with a brush and water. All previously used pots were examined to exclude the 
use of sueli as had formerly been used for soils containing high percentages of 
soluble salts, but such examination was not always successful in eliminating the 
undesirable pots, as was afterwards evident. In the Diablo, Altamont, and Han- 
ford soils the quantity of soil used was five kilos per pot. In the San Joaquin 
soils six kilos were used. 

Euougli soil was collected to fill eighteen pots. Tliis would allow for the 
arrangement of six sets of triplicates of every sample ; and tlie planting of a dif- 
ferent crop in each of tlie sets would allow for the growing simultaneously of six 
different crops on every soil. For example, there were placed together in the 
greenhouse and considered as a unit in the culture work the series of the Diablo 
clay adobe, including three pots of the sample taken from San Juan Capistrano, 
three from that taken near Los Angeles, three from that of the San Fernando 
valley, and lastly three from the sample taken in the Danville region. This group 
of pots was planted to oats, barley, bur clover, or any one other crop. The pots 
were kept together in the greenhouse, that the conditions for each one in the set 
would be as nearly uniform as possible, for even a slightly different location in 
the greenhouse was found to affect the crop appreciably. The other five sets of 
pots were similarly treated. No fertilizing materials were added to any of the 
soils. All were used in tlieir normal condition. The aim was to compare the crop 
producing power of tlxe representatives of a given type of soil from various 
localities. 

Several crops were grown, as the desire was to get a series of plants that 
would grow well under greenhouse conditions, and act as indicators. It was 
known that barley was about the best crop to use, but supplementary plants were 
desired. Barley, wheat, oats, rye, millet, milo, cowpeas (black eye beans), soy 
beans, beans (small white), bur clover (Medicago denticulata) , sweet clover (Meli- 
lotus indica), and oats and bur clover in combination were tried. Some were 
a marked success under greenhouse conditions, and others were practically total 
failures; the better crops were given by barley, soy beans, bur clover, and millet. 
Sweet clover gives excellent results. This wide range of varieties of plants was 



191fl] Pendlcl on: A Study of Soil Types 489 

necessary because of the fact that it was desired to grow two crops a year on the 
soils. The winter crops will not do well in summer, and vice versa, even though 
the summers in Berkeley are relatively cool, and tliough the greenhouse was 
whitewashed during the summer months. 

The seed was obtained in most eases from tlie Division of Agronomy of the 
Department of Agriculture of the University of California. Such varieties as 
were not available from this source were obtained from the commercial seed 
houses in San Francisco. 

Usually the seed was planted directly in the pots, using sufficient seed to be 
sure that enough would germinate and grow to give the desired number of plants 
per pot, usually six. After the plants were well established, and before there was 
any crowding in the pots, the plants were thinned. In some cases an insufiicient 
number of plants germinated to give the desired number per pot. Difficulty was 
found in getting the soy beans and eowpeas to germinate, especially in the 
heavier soils. This was overcome by sprouting the seeds in an incubator and 
planting them when the radicle was half an inch long or more. An excellent stand 
was thus obtained. 

No actual measurements of the height of the plants, or the length of leaves 
were made in the greenhouse work. But photographs were taken, and in these 
photographs the attempt was made to secure representative records of the entire 
series, without photographing the crop in every pot. The usual procedure in the 
Altamont and Diablo series was to photograph two pots out of each set of tripli- 
cates, an attempt being made to select average, representative pots. In the large 
Hanford series one rei^resentative pot of each set of triplicates in each crop 
series was photograplied, and three representative sets of triplicates were also 
photographed. Thus some of the pots appear twice, and allow of comparisons. 

If any doubt be entertained as to the relative weights of the crops in the pots 
pliotographed as compared with those not so recorded, the relative weights of the 
crops may be easily obtained by referring to the tables of dry weights. In prac- 
tically every case the pot label can be read from the photograph. The method of 
labeling is exemplified as follows : 

6 Soil sample no. 6 (Diablo clay adobe from Danville). 

W Wheat, first crop. 
2 Pot 2 of the triplicate set first planted to wheat. 

CP Cowpeas, second croj). 

During the growth of the crops, notes were taken as to the relative growths and 
the general conditions of the plants. 

When the crop had ceased growing it was harvested, whether or not it was 
mature in the sense of having set and developed seed. The plants from a given 
pot were put in a paper bag, labeled, and placed in the drying oven for 24 hours. 
The plants were weighed when dry and cool. If any mature seed was produced 
it was weighed separately. 

Between the first and second crops the soil was allowed to rest from two to 
three weeks or longer. Each pot was emptied and the soil passed through a 
quarter inch screen before replacing in the pot. This broke up the lumps and 
removed most of the roots. The roots were not saved. The weight of tlie roots 
would have been interesting, but their recovery, especially from the heavy soils, 
would have involved careful washing, and the loss of much of the soil. It was 
thought that some washing would be necessary, even in the Hanford series, in 
order that the resulting figures might be at all accurate. 



490 Uniiersity of California Ptiblications in Afjricvltural Sciences [Vol. 3 

APPENDIX B 
SOIL SAMPLE LOCATIONS 

Field Notes on the Soil Samples Collected 

No. 1 — Diablo Clay Adobe 
Location: A little over a mile east of San Juan Capistrano, Orange County. On 
the lower slopes of the hills to the south of San Juan Creek. Sample sta- 
tion is on a little shoulder running northwest, between Mr. Echenique 's 
house and the fence following the road to Prima Deshecka Canada. Ap- 
proximately one-quarter mile from the above house. 
Soil: 0-12 inches — Dark gray adobe; much cracked. 

12-36 inches — Soil becomes gradually lighter in color, approaching a light 

bluish gray mottled with brown. 
36 inches — The subsoil becomes a silty clay loam in the lower depths. 
History: The field was pastured up to and including 1906. From 1907 to date 
the field has been annually planted to barley. Data from Mr. Echenique, 
the owner. Sample collected August 19, 1917. 
Depths of horizons: 

1-A 0-12 inches. 1-B 12-24 inches. 1-C 24-36 inches. 

No. 2 — Diablo Clay Adobe 

Location : One and three-quarter miles east of southeast of Eastlake Park, Los 
Angeles. Station is 0.7 mile by secondary road south of Pacific Electric 
railroad crossing, and 1.2 miles southeast of the Southern Pacific railroad 
crossing. Station is about 150 feet up the hill to the west of the road, in 
grain field, and 7.5 feet south of a 10 or 12 year old eucalyptus grove. 
The road, going south, emerges from the grove, and is then flanked by pep- 
per trees. 

Soil: 0-12 inches — Dark gray to almost black, but with a shade of brown rather 
than a bluish gray. 
12-24 inches — Dark grayish brown clay adobe, becoming a little ligliter with 

depth. 
24-36 inches — Dark brown with soft, whitish fragments. Fragments probably 
the partially weathered parent rock, though no outcrops of the rock were 
seen in the vicinity. Previous to the collection of the sample, Mr. E. C. 
Eekman, who mapped the area as the Bureau of Soils representative, said 
in substance : ' ' We have no good Diablo in the area ; the body I am 
directing you to is as good as any, but it is pretty brown. ' ' 

History: Property owned by Mr. Huntington. Farmed to grain the past 2 
years; pasture previously. Data from the son of the tenant. Sample col- 
lected August 20, 1915. 

Depths of horizons: 

2-A 0-12 inches. 2-B 12-24 inches. 2-C 24-36 inches. 

No. 3 — Altamont Clay Loam 
Location: 1.4 miles southeast of Walnut, Los Angeles County, on the shoulder of 
a low hill, about 200 feet east of the wagon road running south through 
the hills. The station was selected so that the texture was about right, 
for in a very short distance there were variations from a heavy dark clay 
loam or clay adobe to the light clay loams. 



1919] Pendleton : A Study of Soil Types 491 

Soil: 0-36 inches — A medium textured brown friable clay loam. The soil column 
throughout was more or less filled with small soft whitish fragments, por- 
tions of the parent rock. 
36 inches — The weathered parent rock was encountered. 
History : A. T. Currier, owner. The field is in pasture, and has not been culti- 
vated for forty years, to the knowledge of the ranch foreman. The soil is 
probably virgin. Sample collected August 20, 1915. 
Depths of horizons: 

3-A 0-12 inches. 3-B 12-24 inches. 3-C 24-36 inches. 

No. 4 — Altamont Clay Loam 

Location: On a hillside a few feet above the Cahuenga Pass (Burbank road), 
near Oak Crest, Los Angeles County. Just a few feet from the XJ. S. 
Bureau of Soils station for the type in the San Fernando area. (For map, 
see the map under sample no. 25.) 

Soil: 0-14 inches — A dark brown clay loam. 

14-36 inches — A yellowish brown loam, grading into the weathered, thin bed- 
ded shales at about 36 inches. 

History: Eoadside, above the big cut on the road, probably never tilled. The sur- 
face is not so steep but that it could be well tilled; some of the soil in 
the immediate vicinity is cultivated to grain. Sample collected August 21, 
1915. 

Depths of horizons: 

4-A 0-12 inches. 4-B 12-24 inches. 4-C 24-36 inches. 

No. 5 — Diablo Clay Adobe 

Location: About % a mile north of Calabasas, San Fernando Valley, Los Angeles 
County. Tlie station is some distance up the hill to the west of the road 
running north from the Calabasas store. The sample was collected near 
the top of the hill, to the northeast of the oak tree. 

Soil: A dark gray to black typical clay adobe. Distinctly heavy. Digging was 
very difficult, the soil coming up in large, very hard clods. The soil was of 
about the same color and texture down to the bedrock at 26 inches. The 
bedrock is a heavy claystone or shale. 

History: John Grant, Calabasas P. O., owner. The land has been dry farmed 
to grain. Presumably there had been no additions of fertilizing materials 
to the soil. Sample collected August 21, 1915. 

Depths of horizons: 

5-A 0-14 inches. 5-B 14-26 inches. 26 inches. Parent rock. 

No. 6 — Diablo Clay Adobe 

Location: In Contra Costa County, V2 mile west of Tassajero; 6 miles east 
and a little south of Danville. Station about 150 feet up the hill to the 
south of the road, that is, about one-third of the way up the hill. 

Soil : 0-34 inches — A black or dark gray clay adobe, moist at 10 inches. 

34-72 inches — A dark grayish brown subsoil, becoming lighter below the third 
foot. No bedrock within the 6 foot section, nor was there any sign of any 
outcrop in the vicinity. The slope of the hill moderate, the exposure 
north. The sample was collected with the assistance of Mr. L. C. Holmes 
and Mr. E. C. Eckman, both of the XJ. S. Bureau of Soils. They pro- 
nounced the station typical. 



492 University of California Publications in Agricultural Sciences [Vol. 3 

History: Property owned by J. J. Johnson. The field has been farmed to grain 
for probably 60 years. Formerly the rotation was pasture one year, and 
grain one year; now the practice is grain two years, and pasture one year. 
Sample collected September 2, 1915. 

Depths of horizons: 

6-A 0-12 inches. 6-B 12-24 inches. 6-C 24-3G inches. 

No. 7 — Altamont Clay Loam 

Location: On the Mission Pass road, a little less than 2 miles south and a little 

west of Sunol, Alameda County. About 100 feet above the road, between 

wooden electric power poles nos. 92/30 and 92/31. 
Soil: 0-34 inches — A medium brown clay loam, considered typical by Mr. L. C. 

Holmes and Mr. E. C. Eckman of the U. S. Bureau of Soils. There were 

slight changes in texture. 
34 inches — A stiff clay horizon. 
Inspection of a deep cut on the roadside near the location of the sample 

station showed that at 6 feet and deeper there existed a heavy reddish clay. 

In the immediate locality the road sections showed that the parent rock 

was deeper than the 6 foot section. The slope of the land at the sample 

station was quite steep. 
History: Tom Burns, Irvington, owner. Field has been in pasture for the past 3 

years at least, and probably for a much longer time. Sample collected 

September 2, 1915. 
Depths of horizons: 

7-A 0-12 inches. 7-B 12-24 inches. 7-C 24-36 inches. 

No. 10 — San Joaquin Sandy Loam 

Location: North Sacramento, Sacramento County; % mile east of tile factory, 
across the road; opposite poles 57/32 and 57/33, 75 feet southeast froni the 
State Highway. 

Soil: 0-26 inches — A brownish red sandy loam, slightly hog wallowed, and very 
slightly rolling. 
26-36 inches — A sandy clay loam. 
36 inches — A hard hardpan. 

History: Owner not known, the district now being subdivided, the property being a 
portion of the old ' ' Hagan Grant. ' ' A near-by resident gave the following 
information: "The land has not been cultivated for the past 15 years or 
more. The land is said to have been farmed to grain at one time for a few 
years, but the ' soil is too light for wheat, it grows nothing but filaree. ' ' ' 
The principal use has been for cattle and sheep pasture. Sample collected 
March 28, 1916. 

Depths of horizons: 

10-A 0-12 inches. 10-B 12-24 inelies. 10-C 24-36 inches. 

No. 11 — San Joaquin Sandy Loam 

Location: Four miles west of Lincoln, Placer County, at the "Road Corners," 
in the southeast field, 10 feet east of the west fence and 60 feet south of 
the north fence. 



1919J Pcndleion: A Study of Soil Tijpes 403 

Soil: A geutl.y hog wallowed, saudy loam, with some deeper deiiressions, j^rob- 
ably stream channels. Sample slightlj' gravellj'. 
0-12 inches — Brownish or reddisli brown sandy loam. 
12-17 inches — Sandy clay loam or clay, color the same. 
17-23 inches — A stiff reddish brotvii day. 
23 inches — A hard hardpan. 
Histoyij: Mr. Frank Dowd, owner. The land has beeii planted to wheat for the 
past 20 or 25 years; previous to that time it was used for pasture. Six 
to 10 or 12 bushels of wheat, and 8 to 20 bushels of barley is the production 
of this soil in the locality. The soil is usually fallowed on alternate years. 
Land held at from $30 to $50 per acre. Sample collected March 28, 1!)1(). 
Depths of horisons: 

11-A 0-11 inches. 11-B 11-17 inches. 11-C 17-23 inches. 



No. IS — San Joaquin Sandy Loam 

Location : About 6 miles west of Wheatland, Sutter County. Near a road corner, 
in a little swale west of a knoll, 15 feet east of the westerly fence of field, 
and 150 feet south of the north line of the westerly road. 
Soil: Te.xture slightly heavy, and barely enough sand for a sandy loam, but the 
best found for several miles. Color brownish red, the same throughout the 
entire depth. 
0-18 inches — Light, fine textured, sandy loam. 
18-31 inches — Heavy sandy clay loam, running into a stiff clay. 

31 inches — Hardpan, sandy and somewhat soft. The ground was very 
moist at this time. 
History: Very evidently pasture for sheep and cattle. No signs of having been 
cultivated for several years, at least. The cover is of a number of low 
annuals — Ortltocarpus, Trifolium, Centaurea, and others. Sample collected 
March 29, 1916. 
Depths of horizons: 

12-A 0-12 inches. 12-B 12-18 inches. 12-C 18-31 inches. 



No. 1.3 — San Joaquin Sandy Loam 

Location : Three and three-quarters miles east of Elk Grove, Sacramento County. 
On the Sheldon road, about 30 feet northwest from the fence on the north 
side of the road. About 200 feet southwest from where a house formerly 
stood. 
Soil: A reddish brotvn sandy loam, approaching a loam; becoming redder in 
color with increasing depth. 
0-14 inches — Heavy sandy loam. 
14-22 inches — Clay loam. 
22-29 inches — Heavy clay loam. 
29 inches — Compact hardpan. 
History: Waekman Brothers, Elk Grove, owners. The land has not been plowed 
or farmed for at least 15 years. The land is held at about $50 per acre. 
Sample collected March 30, 1916. 
Depths of horizons: 

13-A 0-12 inches. 13-B 12-22 inches. 1.3-C 22-29 inches. 



494 University of California Publications in Agricultural Sciences [Vol. 3 

No. 14 — Hanford Fine Sandy Loam 

Location: One mile southeast of the Sheldon road, 3% miles east of Elk Grove, 
Sacramento County. On the southwest side of the secondary road, in al- 
falfa field, about 2.5 feet from the fence. Station on a little rise. 
Soil: 0-11 inches — A medium brown micaceous heavy fine sandy loam. 

11-24 inches — A dark' gray to black fine sandy loam, grading into the fol- 
lowing. 
24-36 inches — Brown fine sandy loam. Water table at 32 inches. 
History: Mrs. A. C. Freeman, Elk Grove, owner. Land planted to alfalfa. Good 
growth. No irrigation. Willows as well as alders and river ash along the 
sloughs. Many scattering valley oaks. The land is subject to overflow 
from the Cosumnes Eiver, as it lies low in the river bottom, and shallow 
stream channels and sloughs are frequent. Sample collected March 30, 1916. 
Depths of horizons: 

14-A 0-12 inches. 14-B 12-24 inches. 14-C 24-36 inches. 

No. 15 — Hanford Fine Sandy Loam 

Location: North of Woodbridge, San Joaquin County, along the State Highway, 
less than i/4 mile south of the road running westerly from Acampo to the 
highway. Station in a vineyard, with almond trees along the roadside, 20 
feet northeast of ' ' change telephone pole, ' ' 200 feet nortli of pine tree 
at the gateway on the opposite side of the highway. (For map, see under 
sample 16.) 

Soil: Texture a rather coarse fine sandy loam; it was hard to find a good fine 
sandy loam. Color when moist was a medium brown throughout the 3 foot 
section ; the field color was a light grayish brown. 

History: Mike Nolan estate, owner. The vineyard is of Tokay grapes, 10 to 12 
years old. The land is held at $300 to $400 per acre. It is said to be a 
losing game to farm tliis land to grapes at this valuation. Sample col- 
lected March 30, 1916. 

Depths of horizons: 

15-A 0-12 inches. 1.5-B 12-24 inches. 1.5-C 24-36 inches. 



No. 16 — Hanford Fine Sandy Loam 

Location: Along the road north of Woodbridge, San Joacjuiu County. In a young 
pear orchard about 65 feet west of the highway, and about 9.5 feet north 
of the north abutments of the bridge over Mokelumne Eiver. 

Soil: A medium brown fine sandy loam, similar throughout the soil column of 
three feet. This soil is of the recent, flood-plain phase of the type, though 
this station is not known to have been under water for a number of years, 
at least. There is only a comparatively narrow shelf of this phase between 
the older, higher phase, and the river. 

History: A. Perrin, Woodbridge, owner. The land had always been in brush 
and pasture until it was cleared and planted to pears in 1911. Value 
about $500 per acre. Sample collected March 30, 1916. 

Depths of horizons: 

16-A 0-12 inches. 16-B 12-24 inches. 16-C 24-36 inches. 



1919] Pendleton: A Study of Soil Types 495 

No. 17 — San Joaquin Sandy Loam 
Location: A short distance south of the east and west road that runs east to 
Thalheini, San Joaquin County. The station was on a slight knoll 75 feet 
south of a canal, and the same distance east of the secondary road running 
north and south ; not far from a vacant barn. 
Soil: 0-12 inches — Eeddish brown. 
12-24 inches — Slightly redder. 
24 inches — Hardpan. 

The surface had the characteristic hog wallows, and the usual scant vegeta- 
tion of grasses and herbs, "filaree" being abundant; yet all vegetation 
was more abundant than that in pastured fields. 
History : Eev. Frank Hoffman, Acampo, owner. Apparently, the land has not 

been cultivated in recent years. Sample collected March 31, 1915. 
Depths of horizons: 

17-A 0-12 inches. 17-B 12-24 inches. 

No. 18 — San Joaquin Sandy Loam 
Location: Two and one-half miles northwest of Madera, Madera County. Along 
State Highway, 75 to 100 feet southwest of the paved road, at telephone 
pole 92/29 ; across the Iiigliway from the driveway to the house. 
Soil: 0-5 inches — A light reddish brown sandy loam. A noticeable plow pan at 
5 inches. 
5-24 inches — A light brownish red sandy loam, becoming heavier below. 
24-30 inches — Quite compact heavy sandy loam. 
30 inches and deeper — A very compact hardpan. 

Topography very gently rolling, hog wallows well developed, though consider- 
ably degraded by cultivation. Barley grain not growing well in the lower 
spots. 
History: Cropped for probably 20 years to grains; barley at present. Land used 
for pasture previous to grain farming. A good yield is 8 sacks, varying 
from that down to little or nothing. Miller and Lux, owners. Sample col- 
lected April 11, 1916. 
Depths of horizons: 

18-A 0-12 inches. 18-B 12-24 inches. 18-C 24-30 inches. 

No. 19 — Hanford Fine Sandy Loam 

Location: Eight miles east of Waterford, Stanislaus County, near Robert's Ferry 
bridge. About 75 feet west of the road that runs south from the bridge 
onto the bluff. About 450 feet north of the driveway to the Sawyer place. 
Twenty-five feet inside of the fence, in the alfalfa field. 

Soil: Medium brown fine sandy loam; a good brown color when moist. Texture 
somewhat variable, some rounded gravels up to the size of a hen's egg. 
Topography undulating, and more or less terraced, due to the old stream 
channels. 

History: G. H. Sawyer, Waterford, owner. Alfalfa planted in 1915, looks well. 
Land previously planted to barley and wheat, with a production about as 
follows: barley, 14 sacks is considered good; wheat with 12 sacks is good, 
with 6 sacks a low average. Value of the land as recently determined in 
court, in a case of flood damage by a canal break, is $100 per acre. On an 
adjoining piece of land young walnut trees are doing very well. Sample 
collected April 11, 1916. 

Depths of horizons: 

19-A 0-12 inches. 19-B 12-24 inches. 19-C 24-36 inches. 



496 University of California Publications in Agricultural Sciences [Vol.3 

No. 20 — Ban ford Fine Sandi/ Loam 

Location: Near Hopeton, Merced County, 14 miles north of Merced. Less than 
Vi mile north from the road corners, 1.5 feet east of the east fence of the 
road, and 150 feet south of irrigating ditch. 

Soil: A good medium brown fine sandy loam. The color is especially good when 
the soil is moist. The topogi'aphy is slightly uneven because of the old 
stream channels. Going north along the road from the cross roads the 
soil is quite gravelly at first, but the texture gradually becomes heavier, 
with less gravel. At the sample station the texture is a rather heavy fine 
sandy loam. 

History: J. G. Euddle, Snelling, owner. The field is planted to alfalfa, as are 
most of the Hanford soils in the locality. The land is not subject to 
overflow. Sample collected April 13, 1916. 

Dtptlis of hori.zons: 

'20-A 0-12 inches. 20-B 12-24 inches. 20-C 24-36 inches. 

No. 21 — San Joaquin Sandy Loam 

Location : Near Nairn Station, Merced County. About % mile west of tlic rail- 
road, 50 feet north of the private ranch road, and 120 feet east of the field 
gate across the road. About 4 miles northwest of Merced. 
Soil: A good brownish red San Joaquin color. Texture a sandy loam, grading 

into a clay loam or clay at about 24 inches. 
Dcptlis of horizons: 

24-27 inches — A heavy clay. 
27 inches — Hardpan. 

The same was taken from near the top of one of the hog \vallow elevations. 
The topography is gently rolling. 
History: F. W. Henderson, Merced, owner. At the present time the land is used 
as pasture. It has been plowed at some time in the past. The present 
growth of wild herbage (Lepidium, small grasses, Cryptanthe, etc.) is 
meager. Sample collected April 13, 1916. 
Depths of horizons: 

21-A 0-32 inches. 21-B 12-24 inches. 21-C 24-27 inches. 

No. 22 — Hanford Fine Sandy Loam 

Location: A short distance north of Basset, Los Angeles County, on the main 
road north from Basset station. The sample was collected in a walnut 
grove 100 feet east of the road and 250 feet south of the driveway to the 
ranch house. 

Soil: A good medium brown when moist, and a light grayish brown when dry. 
Mr. L. C. Holmes, of the U. S. Bureau of Soils, described the soil at the 
time of collection as being "all a little browner, and -with a little more 
color than a good Hanford. ' ' There was a very slight color change at 
about a foot, the soil below was grayer. Texture a good fine sandy loam, 
with practically no change in the 3 foot column. Topography smooth. 
The texture varies quite rapidly from place to place in the field. Some 
big washes of typical intermittent streams are found not far to the north 
and west. 



1919] Pendleton: A Study of Soil Types 497 

History: C. N. Basset, of Basset and Nebeker, Santa Monica, owner. The land 
is planted to walnuts, and the trees are about 10 years old. They are 
doing well, some replants are found. The trees are irrigated. Sample col- 
lected May 22, 1916. 

Depths of horizons: 

22-A 0-12 inches. 22-B 12-24 inches. 22-C 24-30 inches. 



No. S3 — Hanford Fine Sandy Loam 

Location: South and west of the town of Anaheim, Orange County. Within a 
radius of 20 feet of where the official Bureau of Soils sample was taken. 
Thirty feet east of side road, and 100 feet north of main east and west road. 

Soil: Brown fine sandy loam, possibly a little more silty than no. 22, but not 
heavy enough for a heavy fine sandy loam. Dry field color a light, grayish 
brown. Topograpliy smooth, no stream channels visible. Irrigation in fur- 
rows. Soil similar to about 62 inches, a little more grayish at 18 inches, 
the change being gradual. At 62 inches a gray clean sand, or fine sand, 
was found. 

History : S. J. Luhring, R. F. D. no. 4, owner. The field was planted to Valencia 
oranges in 1913; previously to grapes and miscellaneous crops. Sample 
collected May 23, 1916. 

Depths of horizons: 

23-A 0-12 inches. 23-B 12-24 inches. 23-C 24-36 inches. 



No. S4 — Hanford Fine Sandy Loam 
Location: Southeast of the center of Los Angeles, half way from Magnolia Ave- 
nue on Fruitland Road, to Salt Lake Railroad on the east. South side of 
the road about 60 feet from center, in edge of corn field. Just across 
road from east end of east cypress trees. 
Soil : A medium brown fine sandy loam when moist ; color in the field is a grayish 
brown. Micaceous. Topography level, no stream channels seen nearby. 
Color of body variable. Sample location in the browner phase. Toward 
soutli and east along the railroad and Arcadia Avenue the color is much 
grayer, and even black when moist. Texture within the body is very vari- 
able, though always within the fine sandy loam group. 
0-36 inches — Fine sandy loam, grayer below. 
36-37 inches — Layer of grayish sand and fine sand. 
37-72 inches — Fine sandy loam, heavier in streaks. 
History: C. D. Templeman, R. F. D. no. 2, Box 178, Los Angeles, o-ivner. Land 
has been in truck for 10 or 12 years. Only fertilizer, barnyard manure. 
Sample collected May 24, 1916. 
Depths of lioricons: 

24-A 0-12 inclies. 24-B 12-24 inclies. 24-C 24-36 inches. 



No. 25 — Hanford Fine Sandy Loam 
Location: Near Van Nuys, Los Angeles County; near official sample station. 
Seventy-five feet west of center of road, between fourth and fifth rows of 
apricot trees north from boundary. 



498 University of California Publications in Agricultural Sciences [Vol.3 

Soil: A good medium brown fine sandy loam; the field color a grayisli brown. 
The texture uniform throughout the 3 foot section, with a little gravel occa- 
sionally. Also the texture is variable to about the usual degree, in the 
field distribution. The color is slightly lighter at about 2 feet and below 
throughout the 6 feet, with a little variation in an increasing amount of 
coarser sands. 

History: Chase, Riverside, owner (?). Planted to apricots, 2 years old. Inter- 
planted to melons. Sample collected May 24, 1916. 

Depths of horizons: 

25-A 0-12 inches. 2.5-B 12-24 inches. 25-C 24-36 inches. 

No. S6 — San Joaquin Sandy Loam 

Location: On the high bluffs about 1% miles southeast of Del Mar station, San 
Diego County, close to the road that runs back along the main ridge. About 
50 feet north of the road where it swings south to get around the head of 
the big arroyo from the north. 
Soil: A brownish red sandy loam. Surface covered with a moderate growth of 
the low chapparal common to these exposed ridges. Soil heavily laden with 
iron concretions. Surface has the usual hog wallows characteristic of the 
San Joaquin series. 
0- 6 inches — Eeddish brown sandy loam, many concretions. Dry. 
6-13 inches — Clay (sandy), reddish in cracks, and bluish inside of lumps and 
where not weathered. 
13-22 inches — Clay, mostly bluish gray. 
22-38 inches — Boring very difficult, due to tlie heavy nature of the clayey 

moist material. Color bluish. 
About 40 inches — Hardpan. Very compact. 
Historii : Probably never farmed. Eecently streets cleared, and an attempt made 
to sell lots for building. Value for agriculture — none without irrigation. 
Sample collected May 25, 1916. 
Depths of hoi~izons: 

26-A 0-6 inches. 26-B 6-13 inches. 26-C 13-22 inches. 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



[PENDLETON] PLATE 43 




A gfiK'inl vifw ill tlie yici-iiliouso, wliere all the pot (.■ultiiic \v 
on. The entire right hand bench was devoted to this study, als 
much space not visible in the jirint. 



UNIV. CALIF. PUBL. AGR, SCI. VOL. 



[PENDLETON] PLATE 44 



;/ 






ff 






i 


1 f.lM^ 


:J4 




Diablo Clay Adobe — First Crop 
Pots of saiiio anil different representatives of a given soil type compared. 
Fig. 1. Oats and bur clover. Left to riglit — Soil 1, pot 1 ; soil 2, pot 
soil 5, pot 1; soil 6, pot S. 




Ui.vBLu Clay Adobe — First Crop 
Pots of same and different representatives of a given soil type compared. 
Fig. 2. Oats. Left to right — Soil 1, pot 1 ; soil 2, pot 3; soil 5, j)ot 2; soil 6, 
pot 2. 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



[PENDLETON] PLATE 45 




Pots of .same ami iliffpruiit representatives of a given soil tyiie compareil. 
Pig. 1. Bur clover. Left to right — Soil 1, pot 1; soil 1, pot 2; soil 1, pot 




l)i.\Bi.i.i Clav Adobe — First Ckup 
Pots of same ami different representatives of a given soil type compareil. 
Fig. 2. Bur clover. Left to right — Soil 2, pot 1; soil 2, pot 2; soil 2. ]iot 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



[ PENDLETON 1 PLATE 46 







'./C*-^ 






.^f'- 
;'^^'^^: 




Diablo Clay Adobe — First Crop 
Pots of same and different representatives of a given soil type compared. 
Fig. 1. Bur elover. Left to right — Soil 5, pot 1; soil 5, pot 2; soil 5, pot .S. 




Diablo Clav Adobe — First Crop 
Pots of same ami different representatives of a given soil type compared. 
Fig. 2. Bur clover. Left to riglit — Soil 6, pot 1; soil 6, jiot 2; soil (5, I'ot 3. 



UNIV. CALIF. PUBL, AGR. SCI. VOL. 3 



: PENDLETON] PLATE 47 




Diablo (Jlav Adobe — First Crop 
Pots of same aud rlifferent represontatives of a given soil type compareil. 
Bur clover. Left to right — Soil 1, pot 1; soil 2, pot 2; soil 5, pot 2; soil li, 
pot 1. 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



[PENDLETON] PLATE 48 




Pots of sanu' and ilifferont representatives of a given soil type compared. 

Fig. 1. Dwarf milo in) following oats. Left to right — Soil 1, pot 2; soil 1, 
pot 3; soil 2, pot 1 ; soil 2, pot 3; soil 5, pot 1 ; soil 5, pot 3; soil (>, pot 2; soil (i, 
pot 3. 




Di.\BL() Clay Adobe — Second Cbop 
Pots of same and different rejiresentatives of a given soil type compared. 
Fig. 2. Dwarf milo (b) following oats and bur clover. Left to right — Soil 1, 

pot 1; soil 1, pot 3; soil 2, pot 1; soil 2, pot 3; soil .5, pot 1; soil 5, pot 3; soil 6, 

pot 1 ; soil 6, pot 3. 



UNIV. CALIF, PUBL. AGR. SCI. VOL. 3 



PENDLETON 1 PLATE 49 




Diablo (_'i,.\\ Auoiie — .SEoixn ( fdp 
Pots of same and diffeii'Mt ii'ini'suiitatives of a given soil typo compared. 
Fig. 1. CowjH-as, follouinu wheat, l.t'ft to ri.ulit— Soil 1, ]iot 1 : soil 1, ]iot i 
soil 2 pot 1; soil 2, jiot 2; soil ."i, pot 1 : soil .">, pot 2; soil (i, jiot 2; soil (i, ]iot 




DiAiii.d ('i,.\v Ai>(>i;e — Skciixii (Jkcf 
Pots of same and different representatives of a given soil type compared. 
Fig. 2. Soy beans, following barley. Left to right — Soil 1, pot 1; soil 1, 

pot 2; soil 2, pot 1; soil 2, pot '■'>; soil o, pot 1; soil ."i, pot 2; soil (i, pot 1; soil (i, 

pot 2. 



UNIV, CALIF. FUBL. AGR. SCI. VOL. 3 



PENDLETON J PLATE 50 




Alt.vikixt (_'i,.\v L(i.\m — Heconli (.'kof 
Pots of same and ilifferent represeutatives of a given soil type compared. 
Cow])eas B, following barley. Left to riglit — Soil ?>, pot 1 ; soil 3, jiot- 
soil 4, pot 1; soil 4, pot 3; soil 7, pot 1; soil 7, ])ot 3. 



UNiV. CALIF. PUBL. AGR. SCI, VOL. 3 



PENDLETON] PLATE 51 




Alt.\mont Clay Loam — Second Crop 
Pots of same aud diff'erent representatives of a given soil type r-omparcd. 
Fig. 1. Soy beans A, following oats. Left to right — Soil ?•, pot 1; soil 3, 
pot 2; soil 4, pot 2; soil 4, pot 3; soil 7, pot 2; soil 7, pot 3. 




Ai,T.\.\K'NT L'LAV Loam — Secomi Chop 
Pots of same and different representatives of a given soil type compared. 
Fig. 2. Soy beans B, following Phnseolus. Left to right — Soil 3, pot 2 ; 
sou 3, pot 3; soil 4, pot 1; soil 4, pot 2; soil 7, pot 1; soil 7, pot 2. 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



PENDLETON | PLATE 52 




ALTAiioNT Clay Loam — Second Crop 
Pots of same and different representatives of a given soil type compared. 
Pig. 1. Dwarf milo A, following wheat. Left to right— Soil 3, pot 2; soil 3, 
pot 3; soil i, pot 1; soil 4, pot 3; soil 7, pot 1; soil 7, pot 3. 




Altamont Clay LoAir — Second Crop 
Pots of same and different representatives of a given soil type comjiaied. 
Fig. 2. Dwarf milo A, following bur clover. Left to right — Soil 3, pot 1 ; 
soil 3, pot 2; soil 4, pot 1 ; soil 4, pot 3; soil 7, pot 1 ; soil 7, pot 3. 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



[PENDLETON] PLATE 53 



-V, 



"" '^-^li''-"' ti^'*" iia^'tifiVai iiiiii^' 



K ITL iv'Ail 



Hantoed Fine Sandy Loam — First Crop 
Pots of same and different representatives of a given soil type fonipared. 
Fig. 1. Dwnrf iiiilo A. Left to ri^Iit — Soil 1-i, pot 2; soil 15, pot 2; soil l(i, 

pot 3; soil 19, pot 3; soil 20, pot 2: soil 22, pot 2; soil 23, pot 1; soil 24, pot 2; 

soil 2.5, pot 1. 




II X .rni,-i) Fine SANin I .- \ i i- ikst Crop 
Pots of same ami different representatives of a given soil type compared. 
Fig. 2. Dwarf milo A. Left to right — Soil 15, pot 1; soil 15, pot 2; soil 15, 

pot 3; soil 20, pot 1; soil 20, pot 2; soil 20, pot 3; soil 23, pot 1; soil 23, pot 2; 

soil 23, pot 3. 



UNIV. CALIF. PUBL. AGR. SCI. VOL, 3 



PENDLETON J PLATE 54 




ILvxpuRD Fi.N'E Saxdy LoAii — FiKST Crop 
Pots uf siuue auil diffcrt'iit representatives of a giver soil type eonipiared. 
Fis. 1. Dwarf milo B. Left to right— Soil 14, pot 3; soil 15, pot 2; soil 1(5, 

pot 1 ; so:i 19, pot 3; soil 20, pot 2; soil 22, pot 3; soil 23, pot 3; soil 24, pot 2; 

soil 2.'5, pot 3. 




Haxfiird Fine Sandy LoAJt — First Croi' 
Pots of same and different representatives of a given soil type compared. 
Fig. 2. Dwarf milo B. Left to riglit— Soil 14, pot 1 ; soil 14, pot 2 ; soil 14, 

pot 3; soil 22, pot 1; soil 22, pot 2; soil 22, pot 3; soil 23, pot 1: soil 23, pot 2; 

soil 23, pot 3. 



UNIV. CALIF, PUBL. AGR, SCI, VOL. 3 



PENDLETON 1 PLATE 55 




HANroRD Fine Sandy Loaii — Pirst Crop 
Pots of same and ilifferent representatives of a given soil tyjie conipareil. 
Fig. 1. Soy beans. Left to riglit — Soil 14, pot 1; soil l."i, pot 1; soil lii, 

pot 2; soil IS), pot 2; soil 20, j.ot 3; soil 22, pot 1; soil 23, pot 3; soil 24, pot 1; 

soil 2.J, pot 3. 




lL\NKnl;l> |-'l\!. SaMi\ I,,.A.M h'llj.^l ('l;,,r 

I'ots of same and dift'orent representatives of a given soil type compared. 

Fig. 2. Soy beans. Left to right — Soil 14, pot 1; soil 14, pot 2; soil 14, 
pot 3; soil 16, pot 1; soil 16, pot 2; soil 16, pot 3; soil 23, pot 1; soil 23, pot 2; 
soil 23, pot 3. 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



PENDLETON) PLATE 56 







,v^ . .,r 




^ 




'I 


• i 


' V ' A- 


A' 1 


ti 


i 





f^ 


i i 


i k 


i k 


f 


^- 




3^ 


m 




^^"^^^^r^^pi 


1^^ 





Hanford Fine Sandy Ld.wi l'ii:.~.i <ij,r 
Pots of same ami different representatives of a given s-iil type eoiiipared. 
Fig. 1. Cowpeas B. Left to right— Soil 14, pot 1: soil 14, jiot 2; soil 14, 

pot 3; soil 22, pot 1; soil 22, pot 2; soil 22, pot 8; soil 23, pot 1; soil 23, pot 2; 

soil 23, pot 3. 




Hanford Fine Sandy Liiam — Kikst Ckof 
Pots of same and different representatives of a given soil type compared. 
Fig. 2. Cowpeas B. Left to right — Soil 14, pot 3; soil l.'i. pot 2; soil 16, 

pot 2; soil 19, pot 2; soil 20, pot 2; soil 22, pot 2; soil 23, pot 2; soil 24, pot 1; 

soil 2.5, pot 3. 



UNIV. CALIF. PUBL, AGR, SCI. VOL. 3 



: PENDLETON 1 PLATE 57 




lI-V.\hoKb 1-'|.\K, !Sa.\1iV 1jU.\M SEliiM) ( Kill' 

Pot.s of same ami different representatives of a given soil type compared. 

Fig. 1. Barley, following soy beans. Left to riglit — Soil 14, pot 2 ; soil 15, 
pot 1; soil 16, pot 3; soil 19, pot 3; soil 20, pot 1 : soil 22, pot 2; soil 23, pot 3; 
soil 24, pot 3; soil 2.5, pot 1. 




I1a.\I.'c1K1j Fi.\E .S.iNKV Lo.V.M yECi.lNL) (.'KipI' 

Pots of same and different representatives of a given soil type com]iareil. 

Fig. 2. Barley, following soy beaus. Left to right — Soil 14, pot 1; soil 14, 
pot 2; soil 14, pot 3; soil 19, pot 1; soil 19, pot 2; soil 19, pot 2; soil 19, pot 3; 
soil 23, pot 1 ; soil 23, jiot 2 ; soil 23, pot 3. 



UNIV. CALIF. PUBL. AGR. SCI. VOL, 3 



[PENDLETON] PLATE 58 




Hankohd Fine Sandy Loam — Second Ckoi- 
Pots of same and different representatives of a given soil type compared. 
Wheat, following millet. Left to right — Soil 14, pot 1 ; soil 15, pot 1; soil Ifi, 
pot 1; soil 19, pot 3; soil 20, pot 1; soil 22, pot 1; soil 23, pot 1; soil 24, pot 1; 
soil 25, pot 3. 



I' 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



PENDLETON ] PLATE 5£ 



N 



iwf. iit.^ .'a«'i;^w.^ri,ii'.' '^1! 




Hanford Fixe Saxdv Loam — Secu.vd (.'kcii' 
Pots of sanic aii.l iliffereiit reprosoiitatives of a {tiveii soil type conipart'il. 
Wheat, following iiiillet. Left to right — Soil Hi, pot 1; soil l(i, pot 2; soil 1(5, 

pot 3; soil 22, pot 1; .soil 22, pot 2; soil 22, pot 3; soil 24, pot 1; soil 24, pot 2; 

soil 24, pot 3. 



UNIV. CALIF, PUBL. AGR. SCI, VOL, 3 



[PENDLETON] PLATE 60 




Hanford Fine Sandy Loam — Second Crop 
Pots (if siuiie and different representatives of a given soil t^'pe compared. 
Fii;. 1. Barley, following cowpeas. Left to right — Soil 14, pot 2; soil 15, 
pot 3; soil 16, pot 2; soil 19, pot 2; soil 20, pot 1; .soil 22, pot 3; soil 23, pot 3; 
soil 24, pot 3; soil 25, pot 1. 




Hanford Fine Sandy Loam — Second Chop 
Pots of same and different representatives of a given soil typo compared. 
Fig. 2. Barley, following cowpeas. Left to right — Soil 19, pot 1 ; soil 19, 

pot 2; soil 19, pot 3; soil 20, pot 1; soil 20, pot 2; soil 20, pot 3; soil 23, pot 1; 

soil 23, pot 2 ; soil 23, pot 3. 



UNIV. CALIF. PUBL. AGR, SCI. VOL, 3 



PENDLETON ) PLATE 61 




liAXFciKii F].\E Sandy Loam — Seih: i. < ;:••}■ 
I'ots of sanii" auil cliffi'voiit rrpresciitativos of a given soil type conipared. 
Fig. 1. Oats, folUnving milo. Left tu riglit— 8oil 14, pot 3; soil lo, jiot 2; 

soil 16, pot 2; soil 19, pot 1; soil 20, pot 2; soil 22, pot 1; soil 23, pot 3; soil 24, 

pot 1; soil 25, pot 1. 




Hanford Fine Sandy Loam — Second Crop 
Pots of same and different representatives of a given soil type compared. 
Fig. 2. Oats, following milo. Left to right — Soil 14, pot 1 ; soil 14, pot 2 ; 

soil 14, ]iot 3; soil 15, pot 1; soil 15, pot 2; soil 15, pot 3; soil 24, pot 1; soil 24, 

pot 2 ; soil 24, pot 3. 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



PENDLETON ] PLATE 62 




Hanfurd Fine S.sndy Loam — Second ('kof 
Pots of same and different representatives of a given soil type compared. 

Melilotus indica, following cowpeas. Left to right — Soil 14, Pot 1; Soil 1." 
Pot 3; Soil 16, Pot 2; Soil 19, Pot 2; Soil 20, Pot 1. 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



[PENDLETON] PLATE 63 





Hanfokd Fine Sandy Loam — (Second (_'kop 
Pots of same aud different representatives of a given soil type eoinpared. 
Melilotus indica, following cowpeas. Left to right — Soil 22, Pot 2; Soil 23, 
Pot 1; Soil 24, Pot 1; Soil 25, Pot 1. 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



[ PENDLETON ] PLATE 64 










Hanpord Fine Sandy Loam — Second Ckop 
Pots of same and differeut representatives of a given soil type compared. 
Melilotiis iiicUca, following cowpeas. Left to right — Soil 15, Pot 1; Soil 15, 
Pot 2; Soil 15, Pot 3; Soil 23, Pot 1. 



UNIV, CALIF. PUBL. AGR. SCI, VOL, 3 



■ PENDLETON ) PLATE 65 




llANroEU Fine Sandy Loam — Second Crop 
Pots of same and differeut representatives of a given soil type compared. 

Melilotus iiiilica. following eowpeas. Left to right — Soil 23, Pot 2; Soil 23, 
Pot 3; Soil 25, I'ot 1 ; Soil 25, Pot 2; Soil 25, Pot 3. 



UNIV. CALIF, PUBL. AGR, SCI, VOL. 3 



PENDLETON] PLATE 66 




Hanford Fixe Saxdy Loam — Second Crop 
Pots of same and different representatives of a given soil type compared. 
Bur clover, following milo. Left to right — Soil 14, Pot 1; 8oil 15, Pot 1; 
Soil 16, Pot 2; Soil 19, Pot 1; Soil 20, Pot 1. 








Hanford Fine Sandy Loam — Second Ci:op 
Pots of same and different representatives of a given soil type compared. 

Bur clover following milo. Left to right — Soil 22, Pot 1; Soil 23, Pot 1; 
Soil 24, Pot 1; Soil 25, Pot 1. 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



[PENDLETON] PLATE 67 




HANroRD Fine Sandy Loam — Second Crop 
Pots of same and differcut representatives of a given soil type conijiareil. 
Bur clover, following milo. Left to right — Soil 19, Pot 1; Soil T.l, Pot 
Soil 19, Pot 3; Soil 23. Pot 1 : Soil 23, Pot 2. 




Hanpord Fine Sandy Loam — Second Crop 
Pots of same and different representatives of a given soil type compared. 
Bur clover, following milo. Left to right— Soil 23, Pot 3; Soil 25, Pot 1; 
Soil 23, Pot 2; Soil 23, Pot 3. 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



[PENDLETON] PLATE 68 




t^.\.\ JoAyilN S.\.\i)N L(i.\.\; 
Pots of same and different representatives of a given soil type compared. 
Rye. Left to riglit— Soil 10, pot 2; soil 11, pot 1; soil 12, pot 2; soil 13, 
pot 3; soil 17, pot 3; soil 18, pot 1; soil 21, pot 1; soil 26, pot 1. 



UNIV. CALIF. FUBL. AGR. SCI. VOL, 



r PENDLETON ] PLATE 69 




fS.\x .lo-M^nx Saxiiv L().\m 
Pots of same and ilifferent representatives of a given soil tvpe eompan'.l. 
Fig. 1. Meliliitus iniUra. Left to riglit— Soil 10, pot 1; soil 11, pot .'! ; soil 12, 
pot 2; soil lo. pot 1; soil 17, pot 3; soil 18, pot 3; soil 21, pot 2; soil 21), pot 1. 







*fe^'iipi|i ill iiM^lfar- iiA'f -it^ ^L ^ 





8a .\ Joaquin Sandy Loam 
Pots of same and different representatives of a given soil type eonipared. 
Fig. 2. McUldtus indiva. Left to right— Soil 13, pot 1; soil 13, pot 2; soil 13, 
pot 3; soil 17, pot 1; soil 17, ])ot 2; soil 17, pot 3; soil 2l3, pot 1; soil 28, pot 2; 



soil 



pot 3. 



UNIV. CALIF. PUBL. AGR, SCI, VOL. 3 



[PENDLETON] PLATE 70 




Pots (if saiiie and different representatives of a given soil type eoni])are(l. 
Rye. Left to right— Soil 10, pot 1; soil 10, pot 2; soil 10, pot 3; soil 18, 
pot 1; soil 18, pot 2; .soil 18, pot 3; soil 26, pot 1; soil 2(3, pot 2; soil 2(5, pot 3. 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



PENDLETON] PLATE 71 




Pots of same and different representatives of a given soil type conipareil. 
Fig. 1. Barley. Left to right— Soil 10, pot 3; soil 11, pot 2; soil li!, pot 3; 
soil i:;, pot 1 ; soil 17. pot 3; soil 18, j)ot 2; soil 21, pot 3; soil 26, pot 1. 




San Joaquin Sandy Loam 

Pots of same and different representative.s of a given soil type compared. 

Fig. 2. Barley. Left to right— Soil 10, pot 1; soil 10, pot 2; soil 10, pot 3; 
soil 18, pot 1; soil 18, pot 2; soil 18, pot 3; soil 2(i, pot 1; soil 26, pot 2; soil 23, 
pot 3. 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



[ PENDLETON ] PLATE 72 




San Joaquin Sanuy L(.ia.m 
Pots of same ami ilifferent representatives of a given soil type compared. 
Pig. 1. Oats. Left to right— Soil 10, pot 1; soil 11, pot 1; soil 12, pot 2; 
soil 13, pot 1; soil 17, pot 2; soil 1.S, pot 3; soil 21, pot 1; soil 28, pot 3. 




San Joaquin Sandy Loam 
Pots of same and different representatives of a given soil type compared. 
Fig. 2. Oats. Left to right— Soil 11, pot 1; soil 11, pot 2; soil 11, pot 3; 



soil 17, pot 1; soil 17, pot 2; soil 17, pot 3; soil 21, pot 1; soil 21, pot 
pot 3. 



oil 21. 



UNIV. CALIF. PUBL. AGR. SCI. VOL, 3 



[ PENDLETON ] PLATE 73 




Sa.\- ,liiAt;l-L\ SanIiV Liiam 
Pots uf saiuc ami ilift'ereut representatives of a given soil type conipareil. 
Fig. 1. Wheat. Left to right— Soil 10, pot 1; soil 11, pot 3; soil 12, pot 1; 
soil 13, pot 1 ; soil 17, pot 1 ; soil 18, pot 2; soil 21, pot 1 ; soil 2ii. jiof 3. 




S\x .l().\QUiN Sandy Loam 

Pots of same and different representatives of a given soil type compared. 

Fig. 2. Wheat. Left to right— Soil 10, pot 1; soil 10, pot 2; soil 10, pot 3; 
soil 13, pot 1 ; soil 13, pot 2; soil 13, pot 3; soil 17, pot 1; soil 17, pot 2; soil 17, 
pot 3. 



UNIV. CALIF. PUBL. AGR. SCI. VOL. 3 



[PENDLETON] PLATE 74 




San JoAi^uix .Sandy Loam 
Pots of samo ami different representatives of a given soil type compared. 
Fig. 1. Bur clover. Left to right — Soil 10, pot 2; soil 11, pot 2; soil 12, 
pot 3; soil 13, pot 1; soil 17, pot 3; soil 18, pot 2; soil 21, pot 1; soil 26, pot 3. 




Sax Joaquin Sanuv Loam 

Pots of same and different representatives of a given soil type compareil. 

Fig. 2. Bur clover. Left to right— Soil 10, pot 1; soil 10, pot 2; soU 10, 
pot 3; soil 18, pot 1; soil 18, pot 2; soil 18, pot 3; soil 20, pot 1; soil 20, pot 2; 
soil 20, pot 3. 



UKIVBEBITY OF OAI.IFOBNIA PUBLICATIONS— (Continued) 

AGEICUIiTtJEE. — The Publications of the Agricultural Experiment Station consist of Bul- 
letins and Biennial Reports, edited by Professor Thomas Forsyth Hunt, Director of 
the Station. These are sent gratis to citizens of the State of California. For 
detailed information regarding them address The Agricultural Experiment Station, 
Berkeley, California. 

BOTANY. — W. A. Setchell, Editor. Volumes I-IV, $3.50 per volume; volume V and follow- 
ing, $5.00 per volume. Volumes I (pp. 418), 11 (pp. 360), III (pp. 400), and IV (pp. 
397) completed. Volumes V, VI, and VII in progress. 

Vol. 6. 1. Studies in Nicotiana I, by William A. Setchell. Pp. 1-86; plates 1-28. 

December, 1912 _ 1.558 

2. Quantitative Studies of Inheritance in Nicotiana Hybrids, by Thomas 

H. Goodspeed. Pp. 87-168; plates 29-34. December, 1912 _ 1.00 

S. Quantitative Studies of Inheritance in Nicotiana Hybrids II, by Thomas 

H. Goodspeed. Pp. 169-188. January, 1913 „ .20 

4. On the Partal Sterility of Nicotiana Hybrids made with N. Bylveatrit 

aa a Parent, by Thomas H. Goodspeed. Pp. 189-198. March, 1918.._ J.0 

5. Notes on the Germination of Tobacco Seed, by Thomas Harper Good- 

speed. Pp. 199-222. May, 1913 _... .25 

6. Quantitative Studies of Inheritance in Nicotiana Hybrids, HI, by 

Thomas Harper Goodspeed. Pp 223-231. April, 1915 10 

7. Notes on the Germination of Tobacco Seed, II, by Thomas Harper Good- 

speed. Pp. 233-248. Juno, 1915 15 

8. Parthenogenesis, Parthenocarpy, and Phenospermy in Nicotiana, by 

Thomas Harper Goodspeed. Pp. 249-272, plate 35. July, 1915 . 25 

9. On the Partial Sterility of Nicotiana Hybrids made with N. sylvegtris 

as a Parent, n, by T. H. Goodspeed and A. H. Ayres. Pp. 278-292, 

pL 36. October, 1916 _ _ _ _ „... .20 

10. On the Partial Sterility of Nicotiana Hybrids made with N. sylvestris 

as a Parent, III: An Account of the Mode of Floral Abscission In the 
F, Species Hybrids, by T. H. Goodspeed and J. N. KendalL Pp. 293- 
299. November, 1916 _ „ „ 05 

11. The Nature of the F, Species Hybrids between Nicotiana sylvesirix and 

Varieties of Nicotiana Tabacum, with Special Beference to the Con- 
ception of Beactlon System Contrasts In Heredity, by T. H. Good- 
speed and B. E. Clausen. Pp. 301-346, pis. 37-48. January, 1917 45 

12. Abscission of Flowers and Fruits in Solanaceae with Special Beference 

to Nicotiana, by John N. Kendall. Pp. 347-428, pis. 49-53. March, 
1918 85 

13. Controlled Pollination in Nicotiana, by Thomas H. Goodspeed and Plrie 

Davidson. Pp. 429-434. August, 1918 10 

14. An Apparatus for Flower Measurement, by T. H. Goodspeed and E. E. 

Clausen. Pp. 435-437, plate 54, 1 text figure. September, 1918 05 

15. Note on the Effects of Illuminating Gas and its Constituents In Causing 

Abscission of Flowers in Nicotiana and Citrus, by T. H. Goodspeed, 

J. M. McGee, and E. W. Hodgson. Pp. 439-450. December, 1918 15 

16. Notes on the Germination of Tobacco Seed, III. Note on the Eelation 

of Light and Darkness to Germination, by T. Harper Goodspeed. 

Pp. 451-455. April, 1919 05 

▼ol. 6. 1. Parasitic Florldeae, I, by William Albert Setchell. Pp. 1-34, plates 1-6. 

April, 1914 „.. .35 

2. Phytomorula regularis, a Symmetrical Protophyte related to Coelastnim, 

by Charles Atwood Kofold Pp. 35-40, plate 7 April, 1914 06 

3. Variation In Oenothera ovata, by Katherlne Layne Brandegee. Pp. 41- 

50, plates 8-9. June, 1914 .10 

4. Flantae Mexlcanae Purpuslanae, VI, by Townshend Stlth Brandegee. 

Pp. 51-77. August, 1914 _ 35 

6. The Scinaia Assemblage, by William A. SetcheU. Pp. 79-152, plates 10- 

16. October, 1914 „. .75 

6. Notes on Pacific Coast Algae, I: Pylaiella Postelsiae, n. sp., a New TjTP* 

in the Genus Pylaiella, by Carl Skottsberg. Pp. 153-164, plates 17-19. 

May, 1915 _ .10 



LIBRARY OF CX>NGRESS 



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% 

UKIVESarrY of CAXJFOBNIA publications— (OontlnuM) 

7. New and Noteworthy CallforUan Plants, II, by Harvey Monroe Hall. 

Pp. 165-176, plate 20. October, 1915 .10 

8. Plantae Mexlcanae Piirpuslanae, VII, by T. 8. Brandegee. Pp. 177-197. 

October, 1915 _ .80 

9. Floral Belatlons among the Galapagos Islands, by A. L. Kroeber. Pp. 

199-220. March, 1916 ..„ „ _ .20 

10. The Comparative Histology of Certain Califomlan Boletaceae, by 

Harry S. Yates, Pp. 221-274, plates 21-25. February, 1916 .50 

11. A revision of the Tuberales of CaUfomla, by Helen Margaret Oilkey. 

Pp. 275-356, plates 26-30. March, 1916 _. .80 

12. Species Novae vel Minus Cognitae, by T. S. Brandegee. Pp. 357-361. 

April, 1916 _ 06 

13. Plantae Mexlcanae Purpusianae, VTII, by Townshend Stith Brandegee. 

Pp. 363-375. March, 1917 _.. .15 

14. New Pacific Coast Marine Algae, I, by Nathaniel Lyon Gardner. Pp. 

377-416, plates 31-35. June, 1917 40 

15. An Account of the Mode of FoUar Abscission in Citrus, by Robert W. 

Hodgson. Pp. 417-428. February, 1918 10 

16. New Pacific Coast Marine Algae, II, by Nathaniel Lyon Gardner. Pp. 

429-454, plates 36-37. July, 1918 25 

17. New Pacific Coast Marine Algae, m, by Nathaniel Lyon Gardner. Pp. 

455-486, plates 38-41. December, 1918 35 

18. New Pacific Coast Marine Algae, IV, by Nathaniel Lyon Gardner. 

Pp. 487-496, plate 42. January, 1919 10 

Notes on the Califomlan Species of TriUium. 

1. A Report of the General Results of Field and Garden Studies, 1911- 

1916, by Thomas Harper Goodspeed and Robert Percy Brandt. Pp. 
1-24, pis. 1-4. October, 1916 _ _ _ .26 

2. The Nature and Occurrence of Undeveloped Flowers, by Thomas Harper 

Goodspeed and Robert Percy Brandt. Pp. 26-38, pis. 6-6. October, 

3. Seasonal Changes in TriUium Species with Special Reference to the 

Reproductive Tissues, by Robert Percy Brandt. Pp. 39-68, pis. 7-10. 
December, 1916 „ „ „ SO 

4. Teratologlcal Variations of Trillium sessile yar. giganteum, by Thomas 

Harper Goodspeed. Pp. 69-100, pis. 11-17. January, 1917 SO 



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